High Court Finds Home Office Complaints Process for Immigration Detainees Is Unfair (4 July 2025)

The High Court has ruled that the Home Office’s system for investigating complaints of mistreatment from immigration detainees is procedurally unfair. In a judgment handed down on Tuesday 1 July 2025 in AK v Secretary of State for the Home Department [2025] EWHC 1651 (Admin), Mr Justice Sweeting found that the Home Office’s Professional Standards Unit (PSU) has been operating an unlawful policy and practice when handling such complaints.

Background 

The Claimant, AK, is an Albanian national who was detained under immigration powers from 22 January 2023 until 6 July 2023, at both Brook House and Harmondsworth Immigration Removal Centres (‘IRC’),  pending consideration of potential deportation from the UK. AK had been diagnosed with PTSD, severe depressive disorder and severe generalised anxiety disorder, and there was clear evidence of self-harm and suicidal ideation throughout his detention. The Judge noted the Home Office did not dispute that “the Claimant is a highly vulnerable person and was at particular risk of harm in detention.” 

AK made allegations to the Home Office that on four separate occasions between May and June 2023 he was subjected to inhuman and degrading treatment in breach of Article 3 of the European Convention on Human Rights (‘ECHR’) by detention officers at Brook House IRC and Harmondsworth IRC, including   excessive and unjustified use of force and segregation as punishment and/or to manage his deteriorating mental illness.

The PSU are the Home Office’s internal body responsible for investigating complaints of ‘serious misconduct’ against staff working for the Home Office or their private contractors in IRCs. 

The PSU refused to provide AK with any of the underlying evidence during the investigation, including body-worn camera and CCTV footage and interviews with detention staff  of the incidents, simply  stating  it was not their ‘usual procedure’ to provide such disclosure. AK referred to disadvantages relating to the impacts of his mental illness, his vulnerable position and power imbalance with the detention officers as reasons why the underlying evidence should have been provided to him during the investigation, and argued that the evidence was required to allow him a fair and informed opportunity to give evidence to the PSU and rebut evidence of officers involved.

The PSU steadfastly maintained their position on non-disclosure and the only adjustment made for AK’s mental illness was to forego an in-person interview and allow him to respond to questions in writing. The PSU also refused to investigate AK’s allegations of unlawful use of segregation, despite being intrinsically linked to his allegations of inhuman and degrading treatment, or to consider the impact of his mental illness on how he was treated. 

The PSU dismissed almost all of AK’s allegations in a series of decisions in August and September 2023. They produced four full reports for the Home Office but only provided summary letters of the decisions to AK, thus limiting his ability to understand the decisions and appeal them to the Prisons and Probation Ombudsman (PPO). 

Brook House Inquiry 

AK’s concerns about the limitations of the PSU’s investigation echoed many of the concerns of the Chair of the Brook House Inquiry. The Brook House Inquiry was set up in November 2019 to investigate credible allegations of Article 3 ECHR mistreatment at Brook House IRC in 2017, to understand their causes and to make recommendations to prevent the future recurrence of such mistreatment. It followed a BBC Panorama documentary that revealed widespread physical, verbal and racial abuse of immigration detainees by officers   through undercover filming. The Inquiry’s report was published on 19 September 2023, finding 19 separate incidents where there was credible evidence of   Article 3 mistreatment, including excessive and unjustified use of physical force and segregation on those with serious mental illness. Many of the 19 incidents had previously been investigated by the PSU and allegations dismissed by them. 

The Inquiry Chair, Kate Eves, made a number of findings regarding the adequacy of the PSU’s investigation process, including in relation to the disclosure process, the failure to issue full reports to complainants, and relating to its independence. The Chair made two recommendations relating to the PSU to improve the standards of investigation and to enhance its independence. This included updating the Home Office’s published complaints policy (Detention Services Order 03/2015) to include that:

1. Where there are inconsistencies between any accounts given of events, any evidence relating to those accounts (including footage and documentation) obtained by an investigating officer must be shown to the complainant and to the subject of the complaint, prior to reaching a conclusion.
2. Full reports must be sent to complainants (and their solicitors if applicable). 

Judicial Review Proceedings

AK brought judicial review proceedings on 7 November 2023 against the Home Secretary arguing that the PSU’s policy and/or practice   was unlawful on three grounds: 

1. Ground 1: Common law principles of fairness and natural justice;
2. Ground 2: Section 20 and s 29 of the Equality Act 2010 in failing to make reasonable adjustments to the process for the Claimant taking into account the disability arising from significant mental illness;
3. Ground 3: The Defendant’s investigative duties under Article 3 ECHR to an independent, speedy, fair and effective investigation into a credible allegation of mistreatment read alone and/or with Article 14 ECHR.

The Judge found in favour of AK’s main ground that the PSU’s policy and practice applied in the investigation of his allegations were unlawful and contrary to the common law principles of fairness and natural justice.

The Judge was particularly concerned that the PSU was taking a  general approach to refusing to disclose underlying evidence to complainants during the investigation process, as opposed to reviewing this on a proper case-by-case basis. He found:

81. Drawing the threads together, the evidence indicates that the PSU applied a consistent approach to disclosure in the Claimant's case, characterised by the withholding of underlying evidence such as video footage and witness accounts. This approach was described by the Defendant as a "usual procedure", but as the Claimant argues, its application was not based on the specific facts and needs of his case, but rather a standard practice of non-disclosure. The very description of it as "usual procedure" or even "established practice" suggests a level of consistency that goes beyond individual discretion. On the material before me, I find that the PSU's handling of disclosure in the Claimant's case was conducted pursuant to a discernible policy or practice of generally withholding underlying evidence from complainants, rather than a flexible, case-by-case approach.

86. the investigation's findings directly affect his ability to pursue his allegations of mistreatment further, including via the PPO or potential civil claims. A decision by the PSU not to uphold a complaint, even if not formally an "adverse decision" against the Claimant personally, is functionally adverse to the Claimant's case and his legitimate interest in seeing his allegations properly investigated. The principles of natural justice are not confined to criminal or disciplinary proceedings but apply to any decision-making process by a public body that affects an individual's rights or interests. The Claimant has a clear and significant interest in the fair and effective investigation of his allegations of mistreatment.

91. For the reasons set out above, I find that the Claimant's case on Ground 1 is made out. The PSU procedure, as it was applied to the Claimant's complaints, failed to provide him with a fair opportunity to participate effectively in the investigation by denying him access to the underlying evidence necessary to understand, comment on, correct, or contradict the material considered by the investigator. This constitutes a breach of the Claimant's right to procedural fairness under common law…”

Representation

AK was represented by Lewis Roach-Kett, Nicholas Hughes and Caspar Kwint of Duncan Lewis’ Public Law Department. They instructed Stephanie Harrison KC and Emma Fitzsimons of Garden Court Chambers.

Lewis Roach-Kett, Public Law Solicitor at Duncan Lewis, said of the judgment: “Our client is a highly vulnerable individual with a history of trauma and mental illness. Throughout his detention, he showed clear signs of mental deterioration and increased suicidality and should not have been detained in the first place. Management of his deemed behaviour by way of repeated uses of force and segregation by detention officers only made things worse and reflected many of the incidents of mistreatment recently investigated and identified by the Brook House Inquiry. The investigation by the Home Office of his allegations of mistreatment was compromised by an inflexible approach of denying disclosure of evidence, significantly hindering his ability to fairly participate. It was an approach maintained despite AK making repeated representations relating to his mental illness and despite the Home Office’s  knowledge of the inadequacies of the PSU process from the  evidence to and findings of the Brook House Inquiry. Our client hopes the Home Office now takes urgent steps to review, learn lessons from this judgment and properly reform their complaints policies and practices so that they act as a more effective oversight of misuse of power and abuse than is currently the case.”

Duncan Lewis Solicitors

Duncan Lewis Solicitors, an award-winning law firm, is renowned for its exceptional legal services and commitment to justice. The company employs a team of highly skilled solicitors offering top-tier representation in 25 fields of law, and ranked as top tier by the Chambers and the Legal 500 legal guides, and as one of the top 250 law firms in the country by the Times. Duncan Lewis was crowned Law Firm of the Year at the Modern Law Awards 2023, further establishing its credentials as one of the leading law firms in the UK.

Full judgment now on Bailii - AK, R (On the Application Of) v Secretary of State for the Home Department [2025] EWHC 1651 (Admin) (01 July 2025)