High Court Rules Search Warrants Used at Andrew Mountbatten-Windsor's Homes Were Unlawful

Thames Valley Police has conceded that the search warrants used to raid the homes of Andrew Mountbatten-Windsor at the time of his arrest earlier this year were unlawful, the High Court has been told. The admission followed a legal challenge brought by the former prince, who was arrested on 19 February on suspicion of misconduct in public office and who has consistently denied any wrongdoing.

During a hearing on Thursday, Mr Justice Hilliard said both Mountbatten-Windsor and the police force now agreed that the warrants had been issued unlawfully. The judge confirmed that the warrants had been quashed, but he was careful to stress that this development did not spell the end of the wider criminal investigation.

"The fact that the search warrants were quashed does not bring the investigation to an end or mean that the whole of the investigation is unlawful," Mr Justice Hilliard said. His remarks made clear that while the procedural foundation for the searches had collapsed, the police's broader inquiry remains live and legally intact.

The dispute dates back to the day before the searches, when Thames Valley Police applied for warrants at the Central Criminal Court under sections eight and nine of the Police and Criminal Evidence Act 1984. The court determined that only section eight warrants were required and granted them on that basis. A subsequent legal challenge established, however, that the correct route should have been section nine — a distinction with significant consequences for how sensitive material is handled.

The legal error matters because the two categories of warrant carry different safeguards. Section nine warrants are designed to address the possibility that a search may uncover protected or sensitive material — such as legal advice from a suspect's lawyer, or documents that do not genuinely belong to the suspect, including confidential work-related papers belonging to an employer. Under the strict rules governing searches, police are barred from automatically seizing such material without considering in advance whether it needs protection. In practice, officers who encounter this kind of material during a search should return it rather than use it in their investigation.

Because the warrant granted in this case did not account for the possibility of protected material being seized, the legal basis for the searches was flawed. The law does allow police to seize or potentially retain such material — even in the event of an error — but only if they satisfy additional tests. Thames Valley Police must now persuade a judge that the seized material is likely to be of substantial value to the investigation.

Items seized during the raids continue to be held by police, and a further hearing is expected in 2027 to determine whether the material can be used as evidence. Mountbatten-Windsor opposes the force's bid to retain the evidence, the judge said. The next stage in the legal wrangle is expected to be a behind-closed-doors hearing examining whether police can still hold on to the material under alternative powers designed for precisely this kind of situation.

Explaining why the police were permitted to keep the former prince's possessions for now, Mr Justice Hilliard said: "There would be little point in handing property back if it could then simply be lawfully seized under some other provision." His reasoning suggests the court is weighing practical realities against the procedural failings that led to the warrants being quashed.

A Thames Valley Police spokesperson said the agreement that led to the quashing of the warrants related specifically to a decision made by the court regarding the legal basis for the searches, and was not a judgement on the ongoing investigation. The force said it had ensured the court was presented with all the necessary information and paperwork to inform its decision, and that it had followed the correct legal processes throughout.

"We accept the position that the initial court's decision to issue warrants under the specific piece of legislation used was incorrect and therefore these must be legally quashed," the spokesperson said. The force added that legal proceedings are ongoing to decide how material seized during the searches will be managed and whether it can lawfully be retained in support of the investigation.

Thames Valley Police also confirmed that its investigation into alleged misconduct in public office by a man in his 60s from Norfolk remains ongoing, and that officers continue to pursue all reasonable lines of enquiry to progress the case effectively and fairly. The force has not named Mountbatten-Windsor in its statements, in line with its usual practice.

The arrest arose after the US Department of Justice published documents that raised suspicions Mountbatten-Windsor had forwarded confidential information to the convicted sex offender Jeffrey Epstein when he was serving as a UK trade envoy in 2010. He has consistently denied any wrongdoing in relation to Epstein, and his legal team has used a judicial review to challenge the actions of the force's chief constable and the Central Criminal Court in the build-up to his arrest.

The ruling leaves the investigation in an unusual position: the searches that yielded key material have been deemed unlawful, yet the inquiry itself continues, and the evidence remains in police hands for now. The 2027 hearings will determine whether that material can ultimately be relied upon — a decision that could shape the future of the case and test how courts balance procedural safeguards against the practical demands of criminal investigation.