The woman who alleged in a US court filing she was kept as an underage "sex slave" by a Wall Street financier and forced to have sex with Prince Andrew is standing by her story despite Buckingham Palace's strong denial.

The plaintiff, identified only as "Jane Doe #3" in court papers, told British newspaper The Guardian that she refuses to be "unjustly victimised again" after robust denials of the allegations from the palace and also a prominent US lawyer named in the lawsuit.

The story made front-page news in Britain's newspapers on Saturday.

According to the motion filed in a Florida court this week, the woman alleges she was "forced to have sexual relations" with Prince Andrew in London, New York and the Caribbean at the behest of Jeffrey Epstein.

Epstein, a known friend of Queen Elizabeth II's 54-year-old second son, was convicted in 2008 of soliciting an underage girl for prostitution and served a prison term.

No dates for the purported sexual encounters were given, but the woman claimed she was Epstein's sex slave from 1999 through to 2002.

In a strongly-worded response on Friday, Buckingham Palace said that "any suggestion of impropriety with underage minors is categorically untrue".

In a statement issued to The Guardian through her lawyers, the woman said: "These types of aggressive attacks on me are exactly the reason why sexual abuse victims typically remain silent and the reason why I did for a long time.

"That trend should change. I'm not going to be bullied back into silence."

Another man named in the court papers also robustly protested his innocence.

Alan Dershowitz, one of Epstein's defence lawyers whom "Jane Doe #3" was allegedly forced to have sex with on several occasions, told AFP the story was "made up".

He accused the woman of "filing a false and malicious legal proceeding" in an attempt to extort money from his former client.

In a BBC radio interview, the Harvard Law School professor urged Prince Andrew to fight back against the allegations.

"If she's lied about me, which I know to an absolute certainty she has, she should not be believed about anyone else," Dershowitz said.

"You have to fight back with every resource and ounce of energy available to you."
"I will swear under oath - and I challenge them to swear under oath - that it did not happen," he added.

Andrew, the Duke of York, is fifth in line to the British throne and as a naval officer flew helicopters in the 1982 Falklands War.

He was Britain's special representative for international trade and investment for 10 years until 2011.

The prince gave up the business ambassador post following the intense scrutiny he faced over his relationships with Epstein and other controversial figures.

The filing in which he is named is to be included in an ongoing civil case that accuses federal prosecutors of cutting a plea-bargain deal with Epstein without consulting his victims, in violation of the US Crime Victims Rights' Act.

In 2008, Epstein was sentenced to 18 months in prison after pleading guilty to a single Florida state charge of soliciting prostitution. He remains a registered sex offender.