British police say search warrants secured to search properties linked to Andrew Mountbatten-Windsor had been issued unlawfully and must be quashed, but said the investigation into King Charles III’s younger brother is continuing. 

Mountbatten-Windsor, 66, was arrested on ‌suspicion of misconduct in public office in February this year, linked to his relationship with the late American sex offender Jeffrey Epstein, and searches were carried out at properties in Sandringham, eastern England, and Windsor.

The arrest of the former prince and senior royal, eighth in line to the throne, was unprecedented in modern times and a Reuters photo of the ashen-faced former prince leaving the police station made front pages around the world.

However, subsequently Mountbatten-Windsor, who has not made any public comment since his arrest, launched a legal challenge and applied for the search warrants to be quashed.

Thames Valley Police said it now agreed these had not been properly granted by the courts.

"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," a Thames Valley Police spokesperson said on Thursday.

"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."

At a hearing at London's High Court on Thursday, Judge Nicholas Hilliard said the force was applying to keep the seized property, which Mountbatten-Windsor was opposing, and the issue would not be settled until next year.

A spokesperson for Thames Valley Police said it had not returned any material to the royal other than that which was not deemed to be connected to their investigation.

This photo of the ashen-faced Andrew Mountbatten-Windsor leaving a police station in Aylsham in February made front pages around the world. Photo: Reuters/Phil Noble

INVESTIGATION REMAINS ONGOING

While the quashing of the warrants is an embarrassment, it does not stop the police investigation which began after the release of millions of documents by the US Department of Justice relating to Epstein.

Mountbatten-Windsor, the second son of the late Queen Elizabeth II, has always denied any wrongdoing in relation to Epstein, and said he regrets their friendship.

The offence of misconduct in public office, which carries a maximum sentence of life imprisonment, can relate to any serious wrongdoing - from sharing confidential information to corruption and sexual misconduct.

Police have said their investigation, which relates to Mountbatten-Windsor's time as a British special representative for trade, between 2001 and 2011, would be lengthy and incredibly complex.

He was forced to quit all official royal duties in 2019 over his ties with Epstein, and was then stripped of his ⁠titles and honours by his older brother in October 2025 after further revelations about their relationship.

Epstein was found dead in his Manhattan jail cell in August 2019 in what was ruled a suicide.

Meanwhile, a Buckingham Palace source has said the former prince had been told that money provided from private funds by King Charles should not be used to fund his legal challenge.