A Norwegian escort told a court Monday that Boy George manacled him to a bedroom wall and beat him with a metal chain after accusing him of hacking into his computer.
The former Culture Club singer is on trial for the false imprisonment of 29-year-old Audun Carlsen.
The 47-year-old singer, who is standing trial under his real name, George O'Dowd, denies the charge.
Carlsen told London's Snaresbrook Crown Court that he met the singer through a Web site and went to his London home for a naked photo shoot. After the encounter Boy George sent a series e-mails accusing Carlsen of hacking into his computer, but Carlsen nonetheless agreed to return for a second photo session several weeks later in April 2007.
Carlsen told the jury that when he arrived Boy George and another man held him down and beat him before the singer handcuffed him to a hook in the bedroom wall.
"George was slapping me and beating me and punching me and screaming things," Carlsen said.
"I took a bit of time getting the door open and he had a metal chain that he was hitting me with," Carlsen said.
Carlsen said he ran into the street clad only in his underwear. The court was shown photographs of red welts on Carlsen's head and injuries to his arm which he said had been inflicted during the attack.
Boy George's androgynous image and powerful voice made him an `80s icon, and gave Culture Club hits including "Karma Chameleon" and "Do You Really Want to Hurt Me?"
But the singer struggled for years with drug problems.
In 2006 he was ordered to do community service with New York City's Department of Sanitation after pleading guilty to false reporting of an incident. He called police with a false report of a burglary at his lower Manhattan apartment, and the responding officers found cocaine inside.