US lawyer Alan Dershowitz has admitted he regrets his association with Jeffrey Epstein, his former friend and client, as he bids to clear his name amid allegations he had sex with an underage girl.

In an interview with the JC, Prof Dershowitz, a Harvard academic, said he believes recently-unsealed court documents contain evidence that his accuser is lying.

The allegations against Epstein, who died on Saturday in an apparent suicide while awaiting trial for sex trafficking charges, and Prince Andrew centre on Virginia Giuffre (née Roberts), who claims the late billionaire enlisted her as a sex slave when she was 16 years old.

Mrs Giuffre claims she was also forced to have sex with a number of Epstein’s associates, including Prof Dershowitz, saying in a 2016 deposition that she performed oral sex on him in a limo, and that the pair also had sex on an aeroplane.

Prof Dershowitz, 80, has subsequently launched an active media and legal campaign to clear his name.

He said that “smoking gun documents” exist among a vast tranche of files made public last Friday that relate to a defamation lawsuit Mrs Giuffre has made against alleged Epstein co-conspirator Ghislaine Maxwell.

Among them, he says, is an unpublished book written by Mrs Giuffre about her time with Epstein, in which she makes no claim of having had sex with him. This constitutes a “complete acknowledgment” that the claims against him are false, Prof Dershowitz said.

In the manuscript she claims Prof Dershowitz once walked into a room in which Epstein had recently molested her in order to discuss business for a few moments. Prof Dershowitz denies this happened.

Mrs Giuffre’s book does not repeat the allegations she made in 2016 but, according to American reports, does write Prof Dershowitz had a “taste for the young and beautiful” and that this formed the basis of his “blooming business relationship” with Epstein.

Prof Dershowitz said: “She puts a lot of people in who she had sex with who aren’t famous. And she doesn’t put me in, and if she had had sex with me obviously I’d be featured.

“I’m more famous than the people she put in the book. Obviously that was a complete acknowledgment that she never had sex with me.”

Prof Dershowitz also pointed to Mrs Giuffre’s apparent correspondence with Sharon Churcher, a former Mail on Sunday reporter, who advised her to include him in the book.

It is claimed by US press reports to read: “Don’t forget Alan Dershowitz… [Jeffrey Epstein’s] buddy and lawyer...good name for your pitch as he repped Claus von Bulow and a movie was made about that case… title was Reversal of Fortune. We all suspect Alan is a pedo and tho no proof of that, you probably met him when he was hanging out with [Epstein].”

Ms Churcher declined to comment.

In April, Mrs Giuffre filed a defamation suit against Prof Dershowitz. He has filed a motion to have it dismissed, and an update is expected next month.

Boies Schiller Flexner, the law firm representing Mrs Giuffre, did not return a JC request for comment.

Sigrid McCawley, a partner at the firm, told the Daily Beast: “The denials of those accused of participating in Jeffrey Epstein’s horrific sex trafficking operation are predictable and have long been anticipated.

“Virginia Roberts-Giuffre is a survivor and a woman to be believed. She believes a reckoning of inevitable accountability has begun.”