It has been a bitter back and forth between prominent US lawyer Alan Dershowitz and a woman who claims she slept with him when she was underage.
Mr Dershowitz is suing for defamation and wants the woman's lawyers disbarred.
Now the lawyers have themselves launched a counter-claim for defamation against Mr Dershowitz.
Prince Andrew, who is also mentioned in a civil case in Florida, has said allegations he had sex with a woman when she was underage are "false and without any foundation".
ITV News Correspondent Lewis Vaughan-Jones reports.
How the allegations that a woman was forced to have sex with Prince Andrew while she was underage unfolded.
Buckingham Palace has said any suggestion Prince Andrew was involved in "impropriety with under age minors is categorically untrue".