London-based judge says error ‘does not bring investigation to an end’ as police probe disgraced former royal.

Police in the United Kingdom have agreed that warrants they secured to search properties linked to Andrew Mountbatten-Windsor ⁠had been issued unlawfully and must be quashed, but they say the investigation into King Charles’s younger brother is ongoing.

High Court Justice Nicholas Hilliard said on Thursday that the Thames Valley Police had made a “significant error” in applying for the warrant when they searched the properties of the former British prince, and that police had agreed that “the search warrants were unlawful”.

But he added, “The fact that the search warrants were quashed does not bring an investigation to an end, or mean that the whole of the investigation was unlawful.”

Thames Valley Police said it agreed the warrants were not 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.

“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,” he added.

King Charles III’s brother was arrested on his 66th birthday in February on suspicion of misconduct in public office related to his links to late American sex offender Jeffrey Epstein.

While he was released later that day, he remains under investigation.

Mountbatten-Windsor was also stripped of his royal titles last year following his connections to Epstein, who died in a New York prison in the United States in August 2019.

The disgraced royal has denied wrongdoing.

Police searched his former home in Windsor, west of London, and Sandringham, eastern England, but he subsequently launched a legal challenge over the legality of the warrants obtained.

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

The 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.