A witness claims to have seen Prince Andrew grope Virginia Roberts Giuffre’s butt on Jeffrey Epstein’s “Pedophile Island,” a report said Saturday.

Steve Scully, 70, told The Sun that he saw the disgraced prince kissing and grabbing a young blonde woman wearing a bikini — someone he believes was Giuffre — by a pool on Epstein’s private island, Little St. James.

“He was grabbing her ass and stuff like that. They were kissing,” Scully told The Sun. “He was grinding against her and groping her.”

Scully, who reportedly worked as Epstein’s internet and phone specialist, said that the woman “wasn’t resisting.”

“They were bumping and grinding and fooling around for five, six, seven minutes and they then laid back down on the lounge chairs and continued,” Scully said.

But the new witness said he was shocked by how young the girl looked.

“She stood like a kid would stand behind a parent,” he said.

“They walked off together and I went the other way.”

Last week, the top prosecutor in the US Virgin Islands revealed to Vanity Fair that an employee had come forward as a witness.

“An employee told me that he saw Prince Andrew on a balcony out at Little St. James groping girls right out in the open,” Attorney General Denise George said.

In legal papers and in television interviews, Giuffre has repeatedly accused the Duke of York of having sex with her three times, including while she was underage. He was removed from his royal duties in November after a disastrous BBC interview in which he denied bedding — or even knowing — Giuffre and defended his friendship with Epstein.

Andrew and Buckingham Palace have vehemently denied the accusations against him. He went as far as to call her a “very sick girl” to a friend in 2011 after he was first linked to Epstein’s pedophile scandal.

In recent weeks, four Epstein accusers have written an open letter to Andrew — who has refused to speak to authorities — begging him to talk to the FBI about the allegations.

Socialite Christina Oxenberg, who is a distant relative of the royals, said Epstein’s gal pal Ghislaine Maxwell once told her that the pair had everyone videotaped, The Telegraph reported Friday.

“I’ve seen the video rooms- EVERY SINGLE ROOM was being filmed. I’ve even seen some of the pics- why are the feds taking so long with arrests,” Roberts pleaded on Twitter Saturday. “Everyday I wake up hoping that someone has been held accountable and everyday I wake up disappointed. #DoSomethingAlready.”

Giuffre’s lawyer, David Boies, said she does not remember the specific incident described by Scully.

But Boies added that Scully is “a very significant” witness.