Lawyers for an American woman who has accused Prince Andrew of sexual misconduct say they have written to the prince asking him to respond under oath to the allegations.
The letter was allegedly refused by the recipient and returned to them.
The woman has alleged she was forced by the financier Jeffrey Epstein to have sex with the prince when she was a minor in the United States.
In the latest court documents filed in Florida, the woman, known legally as Jane Doe #3, said she knew the prince as a member of the British royal family but that she just called him "Andy", the BBC reported.
In the letter, lawyers wanted to discuss the circumstances around a photograph of Jane Doe #3 and Prince Andrew, as well as the other times she has said they met.
Buckingham Palace has already strongly denied the allegations.
They said they had nothing to add following the filling of the new court papers.
This is the first time the woman, named elsewhere as Virginia Roberts, has given a statement in her own words to the courts.