A former member of Norway's royal family has claimed he was groped by Kevin Spacey at a banquet 10 years ago.

Ari Behn, 45, says the incident happened after the star had hosted a Nobel Peace Prize concert in 2007 alongside Uma Thurman.

Behn, who was married to Princess Martha Louise at the time, claims Spacey grabbed his testicles under the table after asking if he wanted to smoke outside.

"We had a nice conversation, he was sitting right next to me," Behn laughingly told Norwegian radio station P4.

"After five minutes, he says 'Hey, let's go out and have a cigarette' – and then he takes me under the table in the middle of my balls.

"I got more than I bargained for."

Behn, a Danish author and playwright, said he exclaimed at the time: "Eh? Maybe later."

He added: "I had black hair back then and was 10 years younger so was right up his alley."

The former royal last year divorced his wife, who is the only daughter of King Harald V and fourth in line to the throne. The pair, who have three children together, married in 2002.

Spacey is one of the biggest names to lose work and standing in Hollywood since sexual harassment and abuse allegations against film mogul Harvey Weinstein emerged earlier this year.

The actor has already been fired from the Netflix series House of Cards and dropped by his talent agency and publicist.

US actor Anthony Rapp alleged Spacey made sexual advances toward him in 1986, when Spacey was aged 26 and Rapp just 14.

In a statement, Spacey said he did not remember the alleged encounter but apologised if such "drunken behaviour" had occurred.

But dozens more allegations have since been made against him, including one of sexual assault in 2008 against a man then aged 23 which is now being investigated by police in London.

CNN also reported that eight current or former House of Cards workers claim that Spacey made the production a "toxic" workplace. One ex-employee alleges the actor sexually assaulted him.

London's Old Vic theatre, of which Spacey was artistic director, said last month it has received some 20 allegations of "inappropriate behaviour" against the star.

Spacey has not been arrested or charged with any crime.

ari behn,
Ari Behn and wife Princess Martha Louise pictured together in June 2015 Getty