Lawyers for the woman accusing Prince Andrew of sexual assault are seeking testimony from two people in the UK, according to court documents.
Virginia Giuffre’s legal team want Robert Olney, the prince’s former assistant, to provide a statement.
They also want one from a woman who says she saw the royal in a London nightclub with a young woman – around the time Ms Giuffre says she was abused in 2001 after he visited the club.
The duke has repeatedly denied claims.
Earlier this week, the 61-year-old prince failed in his attempt to have the US civil case dismissed.
Judge Lewis Kaplan, who is hearing the case in New York, has asked for witnesses’ evidence to be taken by lawyers by 14 July and said a trial could take place in court later this year.
Ms Giuffre, now 38, claims the late financier Jeffrey Epstein trafficked her to have sex with men, including Prince Andrew when she was 17 – a minor under US law.
In letters submitted to the Royal Courts of Justice in London, her lawyer David Boies requested two individuals in the UK provide evidence.
Seeking testimony from Mr Olney, who is the prince’s former equerry, the letter says Ms Giuffre has reason to believe he has relevant information about Prince Andrews’s relationship with convicted child sex offender Epstein.
This is because Mr Olney’s name appears in publicly-available copies of Epstein’s phone book, lawyers say.
The other letter seeks testimony from Shukri Walker.
The documents say Ms Walker has stated in the press that she was a potential witness to Prince Andrew’s presence at the Tramp club around the time Ms Giuffre says the royal abused her in London after visiting.
They note Prince Andrew, the Queen’s second son, has denied being at Tramp on the night in question or having ever met Ms Giuffre.
Meanwhile, the prince’s lawyers want to question his accuser’s husband, Robert Giuffre, about their household finances and how he met his wife around 2002, according to court documents.
They also want to ask her psychologist, Dr Judith Lightfoot, about subjects they discussed at her sessions and see her doctors’ notes and medicines prescribed.
The legal team argue Ms Giuffre “may suffer from false memories”, and also want to examine Dr Lightfoot about the “theory of false memories”.
Dr Lightfoot and Mr Guiffre, who both live in Australia, would be requested to be examined under oath in person or by videolink, the documents show.
The development comes after Buckingham Palace announced on Thursday that Prince Andrew’s military titles and royal patronages have been returned to the Queen.
“The Duke of York will continue not to undertake any public duties and is defending this case as a private citizen,” the palace said in a statement.