The father of the sex-trafficking victim linked to Prince Andrew has told British TV he believes his daughter's claims she was forced to have sex with the royal.

"I feel really sorry that all this happened. But it did happen, and Prince Andrew should pay for it," Sky Roberts told the ITV network.

He said his daughter, Virginia Roberts Giuffre, was "really brave to be going through all this and to come up against these powerful people".

"I know she’s telling the truth. My daughter is, she’s a good girl, she really is," he said.

Mr Roberts interview with British TV came as pressure continued to grow on Prince Andrew following Ms Giuffre's claims – repeated on the BBC's Panorama on Monday night (British time) – that she was forced to have sex with him when she was 17.

The BBC also revealed an alleged email from the prince to Ghislaine Maxwell, paedophile Jeffrey Epstein's accused ‘madam’, seeking details about Ms Giuffre.

There were also allegations from five new female witnesses that Andrew watched them give massages to Epstein.

Ms Giuffre also reiterated her earlier claims about dancing with the sweaty prince at London club Tramp before she was trafficked to him in a “horrible” encounter.

On Tuesday night, the prince was absent from a formal dinner for NATO leaders at Buckingham Palace, hosted by the Queen. It was the first royal gathering since the sex scandal that has seen him exiled from the royal family.

On Tuesday, US President Donald Trump declined to offer an opinion on the case, saying only that he didn't know Andrew but that it was a "very tough story".

The two men were snapped together in 2000 at Mr Trump's Florida estate Mar-a-Lago and held a breakfast meeting in June during the President's state visit to London. The prince also gave Mr Trump, his wife Melania and daughter Ivanka Trump a personal tour of Westminster Abbey.

Ms Giuffre, now 35, told the BBC she was recruited into Epstein's sex-trafficking network when she was working as a locker room attendant at Mr Trump's Mar-a-Lago club.

"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," Ms Giuffre said, imploring the British public to back her in her quest for justice.

Andrew has denied having sex with Ms Giuffre and maintains he has no recollection of meeting her – despite a photo that appears to show him with his arm around her waist.

Father of Prince Andrew sex accuser says royal 'should pay'_1
Inset: Prince Andrew, Virginia Roberts Giuffre, and Ghislaine Maxwell.

Andrew, 59, has apologised for his association with Epstein, who died in prison in August in what New York City officials ruled was a suicide. He was facing sex-trafficking charges after earlier serving time for other sex offences.

The disgraced prince says he is willing to cooperate with appropriate law enforcement inquiries if required to do so.

He also faces possible subpoenas from women who are suing Epstein's estate who believe Andrew might have valuable testimony about abuse they suffered.

The scandal is one of the worst to grip the royal household in recent decades and has severely tarnished Andrew's reputation.

US law enforcement agencies have not commented publicly on whether Andrew is being investigated for any possible wrongdoing.

Many of the court papers related to the Epstein case are still sealed and unavailable to the public.

British legal experts, meanwhile, are divided over whether Andrew enjoys immunity from prosecution as a senior British royal. The matter has not been tested in court.

-with AAP