Prince Andrew's pal Ghislaine Maxwell allegedly groped a teenage girl during a naked massage watched by paedophile Jeffrey Epstein, a book claims.
The British socialite is accused of sexually assaulting Annie Farmer, then 16, at the financier's sprawling ranch in New Mexico, according to author and lawyer Bradley Edwards.
In the book Edwards, who represents more than 20 of Epstein's victims, details the claims in court of Farmer, who is now 40.
She alleges Epstein and Maxwell took her shopping then back to Zorro Ranch, where she modelled cowboy boots they bought for her.
Ms Farmer claims he then said she "deserved a massage".
"She felt uncomfortable because Ghislaine made her get naked before covering her with a sheet," Edwards writes of her testimony.
Ms Farmer claims Maxwell then massaged her before pulling the covers off, exposing her breasts and rubbing the teenager's chest.
Only when the massage was over did she realise Epstein had been watching them the entire time.
She was at the ranch after Epstein offered to pay for her to go on an educational course in Thailand.
Court papers accuse Maxwell, 58, and Epstein's friends of helping to procure girls for the paedophile to abuse.
The claims in Edwards' Relentless Pursuit: My Fight for the Victims of Jeffrey Epstein will put more pressure on FBI investigators.
The book quotes a witness who claimed the billionaire "wasn't beyond killing someone" to keep his sex addiction alive.
Among the girls Maxwell is accused of recruiting is Virginia Giuffre, who says she was forced to have sex with Prince Andrew when she was 17 at Epstein's direction.
Maxwell and the Duke of York, 60, have denied any wrongdoing.
The Duke said he does not recall ever meeting his accuser. Ms Giuffre, 36, has previously claimed in court papers that Maxwell had sex with dozens of girls.
Another alleged victim, Priscilla Doe, said that in 2006, at Epstein's Little St James island, Maxwell taught her "step by step" the "proper way" to perform a sex act for the paedophile.
On the same trip, Ms Doe, then a 20-year-old dancer, said she was forced to have sex with another woman during which Epstein choked her.
Epstein, 66, killed himself in jail in August awaiting trial for underage sex-trafficking.
Maxwell, who is the daughter of disgraced media tycoon Robert Maxwell, is called his "madam" in court papers.
Yesterday her lawyers were unavailable for comment.
In court in 2015 Maxwell, who is in hiding, rejected allegations she has acted as a procurer for Epstein and "strongly denies allegations of an unsavoury nature".