Australia's The Daily Telegraph reports that a man drugged and sexually assaulted a 13-year-old girl because he believed he was rock star Ozzy Osbourne and had to follow in his footsteps, a Sydney court was told today (August 31).

Arthur Fairwell, 39, is facing a sentencing hearing in the NSW District Court, where he has pleaded guilty to six charges over the assault of the girl and the drugging of her and her mother.

Fairwell met the girl's mother through a telephone dating service in May 2004.

The court has previously been told that he drugged the woman and her daughter with a sedative at their south-western Sydney home before sexually assaulting the teenage girl.

Making submissions on sentence today, defence barrister Greg Scragg told the court Fairwell had discussed his mental state at the time of the offenses with a forensic psychiatrist.

"My client had come to form the belief he was Ozzy Osbourne, the lead singer in the heavy metal rock group known as BLACK SABBATH," Mr. Scragg said.

"He became obsessed with the idea that he had to do what Ozzy Osbourne had done."

Mr. Scragg said Fairwell had learned of a claim that Osbourne had had sex with a 13-year-old girl. The lawyer said that, because of his client's obsessive beliefs, Fairwell felt compelled to follow in the singer's footsteps.

"He was suffering from a delusion that he was Ozzy Osbourne and had to do what Ozzy Osbourne was believed to have done and have sex with a 13-year-old girl," Mr. Scragg told the court.

Judge Helen Murrell said a previous court hearing was told medical evidence that Fairwell was "deliberately putting on a performance to simulate a (psychiatric) condition".

The hearing has been interrupted by frequent vocal outbursts from Fairwell complaining that he was "getting ripped off here".

"People have gone home on more serious charges and I'm still here," Fairwell shouted from the dock in an American accent.

"They haven't given me my medication for two days and I'm sick."