Andrew Mountbatten-Windsor has accused Thames Valley Police of taking personal items during searches of his home, it has been reported.
It comes as the former Duke of York takes legal action against the force.
Mr Mountbatten-Windsor, who is launching a bid to quash search warrants which led to his arrest, instructed lawyers after discovering officers had allegedly removed “private and confidential material unconnected to the criminal investigation”, according to the Telegraph.
He was arrested on his 66th birthday earlier this year on suspicion of misconduct in public office following allegations he shared sensitive information with Jeffrey Epstein during his time as the UK’s trade envoy.
The King stripped his brother of both his right to be a prince and his dukedom late last year over his association with the convicted sex offender.
Mr Mountbatten-Windsor has been granted permission to challenge whether Thames Valley Police acted lawfully over the searches relating to his arrest in February.
A judge at the Old Bailey issued warrants which allowed police to raid Mr Mountbatten-Windsor’s residence on the Sandringham estate and his former Windsor home, Royal Lodge.
On Monday, a judicial spokesperson confirmed a private hearing in Mr Mountbatten-Windsor’s legal claim is due to take place at 2pm on Thursday at the High Court, before Mr Justice Hilliard.
On the same day, it emerged that Mr Mountbatten-Windsor was warned not to use the King’s private money to fund his legal action.
Mr Mountbatten-Windsor receives an annual stipend – the amount of which has not been disclosed – provided by King Charles from his private funds, but a Palace source said it has been made clear that these monies should not be used to fund the judicial review.
The source added Mr Mountbatten-Windsor’s legal defence was a matter for him and his lawyers, and that Buckingham Palace has no role in determining its strategy or actions.
The clarification from the Palace source will be seen as an attempt by the King to distance himself from the legal proceedings.
When Andrew was arrested on February 19, the monarch issued a written statement, insisting “the law must take its course”.
Mr Mountbatten-Windsor and Thames Valley Police have been contacted for comment.
