Andrew Mountbatten-Windsor remains locked in a High Court battle over whether evidence obtained during raids of two of his properties can be used in the criminal investigation into him after police acknowledged the search warrants used were unlawful.

The former Duke of York, who was not present at the hearing,launched a legal claim against the force over the lawfulness of search warrants granted to them by a judge at the Old Bailey in February, which led officers to raid his residence on the Sandringham Estate and his former Windsor home, Royal Lodge, in February.

Mr Mountbatten-Windsor was arrested on his 66th birthday this year following allegations he shared sensitive information with Jeffrey Epstein during his time as the UK’s trade envoy. He was interviewed under caution before being released under investigation, and has denied any wrongdoing.

In Thursday’s ruling at the Royal Courts of Justice, Thames Valley Police and Mr Mountbatten-Windsor agreed that search warrants which allowed officers to raid his properties in Norfolk and Berkshire earlier this year were unlawful and they were subsequently quashed as part of an agreement formalised by the High Court.

While both parties agreed to quash the unlawful warrants, another court battle has begun as to whether Thames Valley Police can use the material seized from Mr Mountbatten Windsor’s premises. The former Duke of York remains opposed to the police having his seized items, but was not in attendance and his barrister making no submissions.

A hearing in the case to be held in private in 2027, meaning the former prince could remain in limbo for several more months before learning if he will be charged with an offence.

Mr Justice Hilliard said a “significant error” was made in the application for the search warrants, and that was “enough to render the warrants, the searches and the material seized unlawful.”

He ruled that police had needed a section nine warrant that dealt with special procedure material including business records and confidential journalistic material, rather than the section eight one the court had determined they needed in February, which just authorised the entry and search of the premises.

Just because the search warrants were quashed, this did not bring Thames Valley Police’s investigation to an end or render it unlawful, he caveated.

“There would be little point handing it back if it could be lawfully seized on some other provision,” he said. “I will have to decide whether the new application is granted or not.”

A Thames Valley Police spokesperson said that the agreement to quash the warrants was not a judgement of their investigation, which is ongoing.

“On 22 July, the High Court quashed search warrants granted on 18 February 2026 for two properties in Norfolk and Berkshire that were searched as part of Thames Valley Police’s ongoing investigation into misconduct in public office by a man in his 60s from Norfolk,” they said. “The agreement that led to the quashing of the warrants relates specifically to a decision made by the court regarding the legal basis for these and is not a judgement on our ongoing investigation.

“We ensured the court was presented with all the necessary information and paperwork to inform their decision, following 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.

“Legal proceedings are currently ongoing to decide how material seized during the searches will be managed and whether we can lawfully retain it in support of our ongoing investigation.

“Our investigation into alleged misconduct in public office by a man in his 60s from Norfolk remains ongoing, and we continue to pursue all reasonable lines of enquiry to effectively and fairly progress this investigation.

“Due to these ongoing legal proceedings, we cannot currently provide further comment.”

Items seized from Mr Mountbatten-Windsor’s properties under the warrants will be subjected to further, ongoing legal proceedings. The former Duke of York will have to battle it out in court for the return of any seized property, which will remain in police custody under the ongoing investigation.

Mark Stephens, of the Howard Kennedy law firm in London, described the hearing as a preliminary skirmish in the broader legal battle.

"It's the first step of [the former] Prince Andrew and his lawyers saying, 'Actually, this is tainted evidence. It was obtained inappropriately,’” Mr Stephens said. "Therefore it should be excluded from any criminal trial."

Police made an application in June under an act which gives judges power to say whether someone in possession of property as a result of an unlawful search warrant can still retain it if it would be lawfully seized on another provision if returned to the owner.

Mr Justice Hilliard will now have to decide whether a new application is granted or not, and has ruled that there is no point in handing the contents back as it could be lawfully seized on some other provision.

As the investigation into Mr Mountbatten-Windsor is ongoing, Thames Valley Police will be allowed to keep the seized material while court proceedings continue to subsequently examine and use it as part of the investigation.

Danielle Reece-Greenhalgh, partner at Corker Binning, has said that the unlawful warrant does not stop the police from examining the items or automatically render any evidence inadmissible in a future trial.

“The question of whether and how unlawfully obtained evidence can be used centres on whether its admission would have such an adverse effect on the fairness of the proceedings that the court ought not to admit it,” she said.

“If the irregularity or unlawfulness goes hand in hand with some significant resulting unfairness which is incapable of remedy, Mr Mountbatten-Windsor may have grounds to argue that whatever material has been uncovered should not be used against him.”

Mr Mountbatten-Windsor has previously denied any allegations of wrongdoing. Since he was forced to leave the Royal Lodge in February and move to the Sandringham Estate in Norfolk, he has rarely been seen in public.

Mr Justice Hilliard said that Mr Mountbatten-Windsor opposes the bid to retain the evidence, with a hearing in the case to be held in private in 2027.

has contacted the former Duke of York for further comment.