LONDON - A backup singer for Joss Stone has accused billionaire Richard Branson of sexual misconduct.

The incident allegedly occurred following a party on his private island of Necker in the British Virgin Islands in 2010.

Antonia Jenae, 44, first posted about the incident on Facebook before sharing more details with The Sun. She said Mr Branson stuck his head between her breasts.

British singer-songwriter Stone and her backup group had been invited to visit his island after a concert.

"Joss and I were like, 'What the hell was that?' Everyone was wondering why I wasn't angry because I'm usually a firebrand. But I was just too shocked," said Jenae.

Mr Branson also allegedly tried to get her to show him her breasts and walk around topless.

A spokesman for Mr Branson said no one seemed upset after the party.

"There would never have been any intention to offend or make anyone feel uncomfortable. Richard apologises if anyone felt that way," the spokesman added.