Police were concerned Andrew Mountbatten-Windsor could block searches at his properties by claiming officers must obtain permission from the King, legal documents have shown.

Thames Valley Police has acknowledged the search warrants used to raid Andrew’s residence on the Sandringham Estate and his former Windsor home, Royal Lodge, in February were unlawful.

Andrew had challenged the warrants, and now documents from the ensuing High Court proceedings revealed the force feared evidence could be lost if they had to seek permission from Buckingham Palace first to search the premises.

Detectives were searching for “paperwork, diaries, business records or other documentary evidence of AMW’s time as Special Representative for Trade and Investment”, documents show.

According to Andrew’s lawyers, police told the Old Bailey judge: “AMW or his legal team may seek to advance that the property belongs to someone else (the King) and that separate legal permission should be sought.”

“Obtaining such consent may not be expeditious and seeking to do so in advance may frustrate the nature and purpose of the search,” they added.

The former Duke of York was arrested on suspicion of misconduct in public office on February 19, his 66th birthday, following allegations he shared sensitive information with Jeffrey Epstein during his time as the UK’s trade envoy.

Andrew was interviewed under caution before being released under investigation, and denies wrongdoing, with the police probe ongoing.

Mr Justice Hilliard said last week that while the King’s younger brother and Thames Valley Police have reached an “agreement” that the warrants were unlawful, police have since launched a bid to retain evidence gathered during the searches in February.

He said Andrew opposes the bid to retain the evidence, with a hearing in the case to be held in private in 2027.

It means that the former prince could remain in limbo for several more months before learning if he will be charged with an offence.