Lawyers for a woman who says an American billionaire forced her into sexual relations with Britain's Prince Andrew when she was 17 want the royal to respond under oath to the allegations.

In a letter filed in a Florida court Wednesday which piles more pressure on Prince Andrew, the lawyers ask him for an interview "regarding interactions that you had with Jane Doe #3 beginning in approximately early 2001."

The request states the interview should only last about two hours and includes a photograph of Prince Andrew, also known as the Duke of York, with his arm around the woman.

The law office of Bradley Edwards, who represents the woman, told AFP it had no additional comment.

The woman alleges she was "forced to have sexual relations" with Prince Andrew, who is now 54, meeting him in London, New York and the Caribbean at the behest of billionaire Wall Street financier Jeffrey Epstein.

She claims Epstein had kept her as a "sex slave."

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

Buckingham Palace has repeatedly and strongly denied the allegations, calling them "false and without foundation."

"Jane Doe #3" made the claim in a motion 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.

The prince is due to speak Thursday at a gathering of the world's business and political elite in the Swiss ski resort Davos, but it is not clear if he will address the allegations.

A Buckingham Palace spokesman said: "We would not comment on speculation about what the Duke might say."