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Proof, expert evidence and credibility in trafficking cases

Written by
Asad Ali Khan
Date of Publication:
21 January 2021

MN v Secretary of State for the Home Department [2020] EWCA Civ 1746 (21 December 2020)

The Court of Appeal has decided that the two-stage procedure provided for by the National Referral Mechanism (NRM) to determine whether a person is a victim of human trafficking, involving an initial decision on whether there are reasonable grounds to believe that a person is a victim, and a subsequent conclusive decision made on the balance of probabilities, complies with the requirements of the Council of Europe Convention on Action against Trafficking in Human Beings 2005 (ECAT), Directive 2011/36 and article 4 of the ECHR. Two appellants (MN, an Albanian national, and IXU, a Nigerian national) appealed against the dismissal of their judicial review applications of decisions made by Home Office decision-makers that they were not victims of trafficking for the purposes of the NRM. The NRM sets out a two-stage identification procedure to determine whether someone was a victim of trafficking. A "Competent Authority", a part of the Home Office, determines whether there are reasonable grounds to believe that a person is a victim. Then, in light of further consideration/investigation, the Competent Authority makes a conclusive decision. Conclusively established trafficking victims are entitled to support under the NRM. Some, but not all, of that support is available also to potential victims identified at the first stage. The Competent Authority made reasonable grounds determinations in favour of both MN and IXU but made conclusive decisions against them. Farbey J (MN) and Mr Philip Mott QC (IXU) dismissed the judicial review claims at first instance.

MN and IXU argued that they were entitled to continue to receive support and protection for as long as there were reasonable grounds to believe that they were trafficking victims and that the second stage in the NRM, at which a conclusive decision was made on the balance of probabilities, was unlawful. They submitted that the Competent Authority had taken the wrong approach in both cases to the expert evidence before it. They claimed that the Competent Authority had taken the wrong approach to assessing the credibility of their accounts. The AIRE Centre and Anti-Slavery International intervened in these appeals and the court allowed the appeals in part. Furthermore, there was in the case of each appeal a ground peculiar to it. These were related to anxious scrutiny, MN argued that in her case Farbey J wrongly held that no duty of anxious scrutiny arose. While she was still a child IXU underwent female genital mutilation and she stated that the FGM was performed for the purpose of an intended forced marriage to an older man. The judge held that that was immaterial to the question whether she was a victim of trafficking because the connection between the FGM and any possible future exploitation was not sufficiently proximate – IXU contended that he was wrong to do so. In the Court of Appeal, this point was called the "nexus" issue, which the court retained as shorthand for convenience (it was not sure that this was entirely apt).

The Court of Appeal

The court overturned decisions of the Home Office that each of the two appellants was not a victim of trafficking on the basis that the Home Office, acting as the relevant Competent Authority decision-maker adopted an unlawful approach to assessing the credibility of each appellant's credibility and considering the medical and other expert evidence in support of their claim to be victims of trafficking.

The court first addressed the legal framework and then examined the standard of proof and expert evidence and credibility. As to the legal background, the court noted that the law relating to the treatment of victims, and potential victims, of trafficking is found in a complicated framework of international and domestic sources. It considered the Council of Europe Conventions, EU legislation and domestic legislation and practice and the court noted that the ECtHR's jurisprudence expounded article 4 of the ECHR in such a way to reflect the provisions of ECAT. Underhill, Baker and Simler LJJ all contributed to the judgment and Underhill LJ delivered the judgment.

(i) Legal framework

As to the legal framework, the court said that the Victims of Modern Slavery – Competent Authority Guidance is the primary source of the obligation, to support trafficking victims, for practical purposes. The guidance does not itself have the status of law. Yet on the other hand, it represents a formal statement of government policy and practice. As Lady Hale said in MS (Pakistan) v SSHD [2020] UKSC 9, discussed here failures to comply with it may on ordinary principles be the subject of challenge by way of judicial review. Indeed, since the NRM is avowedly intended to give effect to the UK's obligations under ECAT. The guidance must be construed so far as possible to give effect to the UK's duties under ECAT and the EU Anti-trafficking Directive 2011/36 and the court explained that where a compatible construction is not possible, obligations under Chapter III of ECAT would be directly enforceable to the extent that they correspond to positive obligations under article 4 of the ECHR. Equally, the obligations under article 11 of the 2011 EU Anti-trafficking Directive are also directly enforceable.

The court applied Aikens LJ's analysis in R (Atamewan) v SSHD [2014] 1 WLR 1959 to hold article 10 of ECAT provides that during the identification process, both potential and established victims should not be removed from a contracting state's territory and should be given assistance under article 12. The court said that article 10 of ECAT distinguished between potential and established victims. Notably, article 12 makes provision regarding victims' needs and required victims to be afforded protection against further exploitation and it provided medical and labour rights to established victims. Furthermore, article 13 required a "recovery and reflection period" for potential victims. ECAT did not require states to grant a right of residence to established victims of trafficking generally.

The European Court of Human Rights (the ECtHR) has held that the general language of article 4 of the ECHR imposes on member states certain positive obligations as regards trafficking. That was first established by Siliadin v France (2006) 43 EHRR 16, but the law was much more fully developed in Rantsev v Cyprus and Russia (2010) 51 EHRR 1. Since then it has been applied and re-stated in a number of later cases, most notably J v Austria [2017] ECHR 37, Chowdhury v Greece (21884/15) and SM v Croatia (2019) 68 EHRR 7 (Grand Chamber). The post-Rantsev jurisprudence developed in more detail the nature of the positive obligations imposed by article 4 as regards trafficking. Indeed, in J v Austria the ECtHR identified three classes of positive obligation, and that classification was endorsed by the Grand Chamber in SM (Croatia). Notably, at para 17 of R (TDT) v SSHD [2018] EWCA Civ 1395, Underhill LJ summarised those duties as (a) a general duty to implement measures to combat trafficking – "the systems duty", (b) a duty to take steps to protect individual victims of trafficking – "the protection duty", sometimes called "the operational duty", and (c) a duty to investigate situations of potential trafficking – "the investigation duty", sometimes called "the procedural duty". The duties in question are not absolute, what is required will depend on the circumstances of the particular case.

The Court of Appeal explained that article 11 of the EU Anti-trafficking Directive had substantially the same effect as article 12 of ECAT and these provisions imposed formally distinct obligations and the court did not understand the government to argue that article 11(2) of the EU Anti-trafficking Directive does not impose a separate duty and the court approved the approach taken in R (Galdikas) v SSHD [2016] EWHC 942 (Admin) where an argument of that nature had been rejected by Sir Stephen Silber who held that article 11(1) and article 11(2) of the Directive provided for identical duties of support but applied in different circumstances. The article 11(1) duty was called the the paragraph 1 duty and article 11(2) duty was called the the paragraph 2 duty in the Court of Appeal's judgment.

(ii) Standard of proof

The court said the nature of the assistance which states are required to accord to victims, or potential victims, depends on which stage of the identification process under article 10 of ECAT has been reached. The position can be summarised as follows.

Notably, the first stage begins when there are reasonable grounds to believe that a person is a victim of trafficking – that is, that they are a potential victim. The effect of articles 10(2) and 13 is that at that stage they must, for at least 30 days, be accorded temporary irremovability and the lesser degree of assistance (relating to core needs) provided for by paragraphs 1 and 2 of article 12. Furthermore, the second stage begins when they have been definitively identified as victims of trafficking at the conclusion of the identification process – that is, when they become an established victim. They must then be accorded not only the assistance required by paragraphs 1 and 2 of article 12 but the more extensive assistance provided for by paragraphs 3 and 4 and the right to a "renewable residence permit" if they can satisfy the conditions specified.

On MN and IXU and the Interveners' case, this two stage approach had to represent two free-standing levels of support, depending on how firmly it can be established that the individual concerned is a victim of trafficking, one to be accorded where there are no more than reasonable grounds for that conclusion, and the other where a definitive conclusion is possible. Rejecting the approach, the Court of Appeal held:

92. … We cannot read the relevant provisions in that way. What article 10 expressly provides for is a single identification process leading to a definitive decision which then attracts the substantive rights provided for in Chapter III. The purpose of the first stage is simply to ensure that persons who may in due course be identified as victims of trafficking are not removed, and are assisted with their essential needs, pending that decision. That is in our view the only natural reading of, in particular, article 10.2: the first sentence provides for the identification process, and the second provides for certain minimum rights "until the identification process … is completed".

The court's view was reinforced by the relevant passages in the Explanatory Report at paras 132 which speaks of "until completion of the identification process establishes conclusively whether or not they are victims of trafficking" and para 135 which states "the benefit, during the identification process, of the assistance measures provided for …". Overall, the provision in the guidance that the right to support was terminated by an adverse conclusive grounds decision was not inconsistent with either ECHR article 4 or the 2011 Directive. It followed that the civil standard of proof was unobjectionable. The court held that:

99. We therefore conclude that the provision in the Guidance that the right to support is terminated by an adverse conclusive grounds decision is not inconsistent either with article 4 of the ECHR or with the 2011 Directive.

20. Once that point is reached it follows that the adoption of the civil standard of proof is unobjectionable, indeed in practice inescapable, and we would reject the appellants' case.

Next the court turned its attention to the issue of expert evidence.

(iii) Expert evidence

The court prefaced its judgment by making a point on terminology and he mentioned the ruling in KV (Sri Lanka) v SSHD [2019] UKSC 10 (discussed here) and noted that in the context of the value of physical scarring as evidence of torture paragraph 187 of the so-called "Istanbul Protocol" makes a distinction between "not consistent", "consistent" and "highly consistent", with further categories of "typical" and "diagnostic".

The court stressed that it is important to distinguish between those cases where an expert is saying no more than that the signs found and/or symptoms reported are consistent with the treatment recounted by the applicant – "mere consistency" cases – and cases where they what they are saying is that they are positively supportive of it. He said that even if the witness does not use the Istanbul categories, the intended meaning will be sufficiently clear from the context. This is important both when considering the report of an expert in a particular case and when considering the case-law.

The court embarked upon a lengthy appraisal of the authorities and summarised the law in the following way. First, the decision whether the account given by an applicant is in the essential respects truthful has to be taken by the tribunal or CA caseworker (for short, the decision-maker) on the totality of the evidence, viewed holistically in line with Mibanga v SSHD [2005] EWCA Civ 367. Secondly, where a doctor's opinion, properly understood, goes no further than a finding of "mere consistency" with the account of the applicant it is, necessarily, neutral on the question whether that account is truthful, the point is in truth obvious and was made in HE (DRC) v SSHD [2004] UKIAT 321. Thirdly, it is open to a doctor to express an opinion to the effect that his or her findings are positively supportive of the truthfulness of an applicant's account (namely, an opinion going beyond "mere consistency") and where they do so that opinion should in principle be taken into account – MO (Algeria) v SSHD [2007] EWCA Civ 1276 and, though less explicitly, Mibanga.

Fourth, such a view may be based on physical findings (such as specially characteristic scarring). However, it may also be based on an assessment of the applicant's reported symptoms, including symptoms of mental ill-health, and/or of their overall presentation and history. Such evidence is equally in principle admissible: there is no rule that doctors are disabled by their professional role from considering critically the truthfulness of what they are told. The court added that in the context of a decision taken by the Competent Authority on a wholly paper basis, a doctor's opinion of the truthfulness of the applicant may be of particular value subject to the next point, i.e. the weight to be given to any such expression of opinion will depend on the circumstances of the particular case. It can never be determinative, the decision-maker will have to decide in each case to what extent its value has to be discounted for reasons of the kind given by Ouseley J at paragraph 18 of his judgment in HE (DRC).

One factor bearing on the weight to be given to an expression of opinion by a doctor that the applicants reported symptoms support their case: they were persecuted or trafficked (as the case may be) is whether there are other possible causes of those symptoms. For the reasons given by Ouseley J in HE (DRC) there may very well be obvious other potential causes in cases of this kind. The court held, in line with SS (Sri Lanka) v SSHD [2012] EWCA Civ 945, that if the expert has not considered that question that does not justify excluding it altogether. It may diminish the value that can be put on their opinion, but the extent to which that is so depends on the likelihood of such other causes operating in the particular case and producing the symptoms in question.

(iv) Credibility

The court noted that the Victims of Modern Slavery – Competent Authority Guidance, first published in March 2016, version 3 made references to "mitigating circumstances" which could affect whether an account was credible. The court also determined that the phraseology was not apt as it implied that the decision-maker should first identify the defects in an account and then decide whether they could be excused. Instead, what was really required was a single process in which the decision-maker assessed the credibility of the core account and the court said:

126. … It is not simply that that phraseology has an inappropriate echo of criminal proceedings. More substantially, it implies an approach under which the decision-taker first identifies the defects in the account of a putative victim and then tries to decide whether they can be excused for reasons of the kind given. That risks being over-mechanistic and does not reflect the real nature of the exercise.

Overall, the court said that Mibanga had made it quite clear that what was required is a single process in which the decision-maker assesses the credibility of the core account given by the putative victim. It is also necessary to take into account those features which potentially call their credibility into question, such as incoherence, inconsistency or delay, alongside factors which may explain those features. Further, the court said that as a matter of language, "credibility" is used a lot in the context both of asylum and trafficking cases and a tendency exists to treat it as having some special technical meaning. But in reality it "connotes no more than whether the applicant's account is to be believed." Similarly, the term "plausibility" is not a term of art and the court added "if terms are used too regularly they sometimes get in the way of the process of common sense decision-making"

(v) Disposal of appeals

In MN's case, the court held that the Competent Authority's reasoning on credibility and expert evidence was not sustainable and needed to be remitted for redetermination and the court was not satisfied that the only conclusion to which the Competent Authority could properly have come was that MN's story was untrue. The trafficking of Albanian women into prostitution in Italy was well known and MN's overall account and her presentation to the expert witnesses were characteristic of those of genuine victims.

The inconsistencies within and between her various accounts were a real problem but at least some at least were explained in her evidence in ways which were not self-evidently untrue. Full weight needed to be given to the evidence (and guidance) about all the real difficulties that victims of trafficking have in telling their stories and this was so not only because of the effects of trauma but because their experiences often engender distrust of authority and sometimes entangle them in deceptions of various kinds from which it is difficult to escape. It was also necessary to heed the caution expressed in the decided case law about judging accounts to be implausible without complete knowledge of the relevant circumstances, and making full allowance for how people can behave in circumstances of stress.

In IXU's case, the Competent Authority noted her claim to have been subjected to FGM in preparation for a forced marriage which was a form of exploitation but it had erred in failing to decide whether IXU's FGM was in fact performed for the purpose of a forced marriage. The court found that there was a question of what degree of nexus (labelled "the nexus issue") there should be between an action, i.e. the FGM, and an intended forced marriage. The decision of whether the act of taking IXU away to subject her to FGM had been for the purpose of subjecting her to a forced marriage required a proper assessment and would be remitted to the Competent Authority (which had also erred regarding expert evidence). Its decision was quashed by the court with the result that her application will have to be determined afresh by a different decision-maker.


This is an excessively lengthy judgment and its sprawl does not make the task of getting justice for victims of trafficking any easier as it is hardly written in plain/simple English. Yet the "essential message" of the court's "possibly over-elaborate discussion" is that the Home Office's decision-makers should in every case assess whether and to what extent any particular expert evidence relied on by an applicant supports their case as a matter of rational analysis. According to the Court of Appeal, observations in the decided cases are useful in drawing attention to likely limitations on the value of specific kinds of evidence, but they should not be considered to lay down rigid rules. The court was of the view that if there are qualifications to the value to be given to a particular piece of evidence, that is not a reason for excluding it altogether and if the said item of evidence has some weight it must go into the overall assessment.

Further, the court added that the conclusions in the authorities concerned specifically with evidence from doctors. It pointed out that applicants in asylum and trafficking cases also adduce evidence from non-medical witnesses, with experience of the kind of persecution or trafficking in question, to the effect that the account which the applicant gives of their experiences is consistent with the accounts given by other established victims. This type of evidence is of a different character from evidence of signs or symptoms assessed by a doctor, and the relevance of consistency is quite different. And if an applicant's account is highly circumstantial in relation to the means used to recruit or transport them or the way in which they were exploited, and the details closely correspond to what other established victims have reported, that will in principle support the truth of their story, but the extent to which it does so will turn on the specific case. The court stated that it will always be necessary to assess the degree of comparability, and a decision-maker will also have to be alert to the possibility of the applicant having been coached to give a convincing account and this should be welcome news in the Home Office where a culture of disbelief exists as regards asylum and trafficking cases.