Panorama's investigation into sex allegations surrounding the Duke of York is "about as bad as it gets for Andrew", one royal writer says.
Penny Junor says the duke's accuser, Virgina Giuffre - seen in excerpts released before the broadcast - comes across as a more sympathetic character compared with his own Newsnight interview.
But she warned there was no way to know which one was telling the truth.
Giuffre, in the interview due to air on BBC One on Monday, claims she was trafficked by Jeffrey Epstein and forced to have sex with Andrew when she was a teenager, which the duke categorically denies.
She said Andrew was "the most hideous dancer I've ever seen in my life" and "his sweat was ... raining basically everywhere".
Giuffre added: "This is not some sordid sex story. This is a story of being trafficked, this is a story of abuse and this is a story of your guys' royalty."
Junor told PA: "This is about as bad as it gets for Andrew.
"Virginia Guiffre sounds very plausible in this interview, while most of Andrew's excuses in his interview with Emily Maitlis were laughable.
"She also comes across as a much more sympathetic character so viewers will warm to her.
"And she was clearly abused by Jeffrey Epstein and one's heart goes out to her.
"She is absolutely right in saying that only one of them is telling the truth but with nothing more than their television performances to go on, we have no way of knowing which of them it is."
Graham Smith of Republic, which campaigns for an elected head of state, said: "This interview is likely to be hugely damaging to Andrew and the royal family.
"The Queen and Charles have known about these accusations for eight years and did nothing until it became a PR disaster.
"Still the royals hide behind palace gates denying the allegations but refusing to do anything that might help law enforcement or alleged trafficking victims in the US and the UK.
"Prince Andrew needs to be properly investigated by the Metropolitan Police and the police in the States."
But Daniel Janner QC warned the BBC ran the risk of a trial by media of the duke.
The founder of Falsely Accused Individuals for Reform (Fair), which campaigns for anonymity before charge in relation to sexual offences, said: "There is a danger in the Prince Andrew case of assuming guilt by association. He is entitled to the presumption of innocence.
"Those making allegations against Prince Andrew should have their evidence forensically tested to ensure they are not motivated by false compensation claims against a lucrative estate."
A statement by His Royal Highness The Duke of York KG. pic.twitter.com/solPHzEzzp— The Duke of York (@TheDukeOfYork) November 20, 2019
© PAA 2019