The Duke of York is alleged to have castigated a member of the royal household as a “f***ing imbecile” after he failed to refer to the Queen Mother by her full title.

The claim is one of a series of allegations about Prince Andrew’s “cruel” and high-handed treatment of royal staff that are highlighted in a new biography of the duke and his ex-wife, Sarah, Duchess of York.

The book also contains new claims about the closeness of Andrew’s relationship with Jeffrey Epstein, the late US paedophile financier. Epstein is alleged to have said of his royal friend: “We are both serial sex addicts.”

The claims by Andrew Lownie, an acclaimed historian and author, will put the duke back in the spotlight after a separate scandal earlier this year about his close ties to a suspected Chinese spy. Andrew, 65, has stated that he severed ties with the alleged agent after he was warned by the authorities.

Portrait of Andrew Lownie at the Oldie Literary Lunch.

The duke’s approach to loyal royal servants is said to have been encapsulated by an incident at Hillborough Castle in Northern Ireland following a severe storm in 2005.

“He could be unbelievably cruel,” Lownie claims. “Andrew asked the head of the household, David Anderson, if there was any damage. ‘Yes, sir,’ responded Anderson. ‘The tree which was planted by the Queen Mother.’ This was followed by a withering silence, then Andrew said in a mocking voice, ‘Did you mean Queen Elizabeth, the Queen Mother?’

“He then asked the poor man how long he had worked for the royal family. Anderson replied, ‘I joined in 1984, sir.’ ‘And you still don’t know the proper way to refer to my grandmother? You fing imbecile. Get out,’” the book alleges.Colin Burgess, a former equerry to the Queen Mother, alleges in the new book that Andrew had a particular catchphrase for staff: “I want this done and I want this done now. Do it!”

Burgess claims the duke’s approach was in stark contrast to the respect afforded to servants by King Charles and his son, William. “I saw [Andrew] about once a month when he came to visit Clarence House and he would talk to the staff, including me, as an officer talks to his subordinates,” Burgess says.

Lownie claims that prior to stepping back from his royal duties in 2019, the duke would dispatch his taxpayer-funded protection officers to collect golf balls that he had driven up the fairway.

The new allegations are recounted in Entitled: The Rise and Fall of the House of York, which is being serialised by the Daily Mail and Mail on Sunday, and will be published next week.

Book cover for "Entitled: The Rise and Fall of the House of York" by Andrew Lownie.

Andrew’s downfall was precipitated by this relationship with Epstein and claims by Virginia Giuffre that she had been forced to have sex with the duke on three separate occasions when she was a teenager. Andrew has always denied the allegations.

In 2022, he reportedly paid £12 million to settle a civil lawsuit brought by Giuffre in the US courts. There was no admission of liability.

Epstein died in a prison cell in New York in 2019, aged 66, while awaiting trial for child sex trafficking offences.

His former girlfriend, the British socialite Ghislaine Maxwell, 63, was jailed in the US for 20 years in 2021 for her role in Epstein’s sex trafficking network.

Maxwell recently pledged to give evidence about Epstein’s connections to powerful figures, including Andrew and President Trump. She is hoping her co-operation might lead to her being pardoned. Last week it was revealed that Maxwell has been moved from her cell in Florida to a minimum security prison in Texas.

Representatives for the Duke of York did not respond to a request for comment.