Fahad Ansari, R (on the application of) v Chief Constable of North Wales Police & Anor

The AF (No. 3) disclosure standard is a binary rule. If it applies, fairness requires disclosure of sufficient information to enable the excluded party to mount an effective challenge. The state must disclose that core minimum or withdraw part or all of its case. If it does not apply, the court follows the governing closed-material regime, including protection against disclosure damaging to national security. The nature and impact of the right affected are central. A challenge to the seizure, retention and examination of mobile-phone data under Schedule 7 to the Terrorism Act 2000 was analogous to a search-warrant challenge, so the standard did not apply.

The claimant, a solicitor undertaking national-security and human-rights work, challenged his detention, questioning and the seizure, downloading, retention and inspection of his mobile-phone contents under Schedule 7 to the Terrorism Act 2000.

The court had authorised a closed-material procedure under section 6 of the Justice and Security Act 2013. The parties proceeded on the assumption that Article 6 ECHR applied. The central issue was whether the disclosure standard in Secretary of State for the Home Department v AF (No. 3) [2009] UKHL 28 applied, requiring disclosure sufficient to enable the claimant to disprove the case against him even where disclosure would damage national security.

1. The AF (No. 3) standard did not apply. The court must first decide whether the case is of a type engaging the standard. If so, fairness requires disclosure of the core irreducible minimum needed for an effective challenge; the state must disclose it or withdraw part or all of its case. If not, the court applies the governing statutory and procedural regime, here the Justice and Security Act 2013 and CPR Part 82 (paras [56]-[65]).
2. There is no general intermediate standard under which a court orders disclosure damaging to national security but insufficient to permit an effective challenge. Tariq v Home Office and Kiani v Secretary of State for the Home Department did not support that approach (paras [56]-[63]).
3. The distinction between forward-looking claims and backward-looking damages claims is unsustainable. Nor is it decisive that legality turns on rationality rather than proof of allegations, since the affected person may possess relevant evidence unavailable to the special advocate (paras [66]-[72]).
4. The applicable considerations include the nature and impact of the right affected and relevant policy considerations. The case was analogous to R (Haralambous) v St Albans Crown Court [2018] UKSC 1: seizure and retention did not impose legal obligations or alter the claimant’s substantive legal position, while any later criminal proceedings would provide ordinary safeguards. Potentially privileged material did not change that conclusion (paras [73]-[77]).
5. Neither defendant was required to disclose information damaging to national security (para [78]).

First-instance judicial review proceedings. The judgment records earlier judgments in the same proceedings dated 6 October 2025, [2025] EWHC 2764 (Admin), and 24 October 2025, [2025] EWHC 3330 (Admin), including authorisation of a closed-material procedure. No appeal stage is stated.