R&B star Chris Brown's 2009 assault conviction is still hanging over him - a Los Angeles judge has ordered an audit of his community service amid concerns he still owes the court several hours.

The Kiss Kiss singer was handed a five-year probation order, as well as six months' community service after he was convicted of assaulting his ex-girlfriend Rihanna.

He was also ordered to stay away from his ex - a ruling that has since been relaxed, allowing the former lovers to work together in the studio and attend the same awards events.

But his community service requirements have not been scaled back and now there are concerns about whether or not he completed the terms of the order properly.

The Associated Press reports a prosecutor in the case has raised questions about the hours Brown served.

Brown was supposed to appear in court for a probation hearing on Monday (17Sep12) but that has been pushed back to give authorities more time to complete a case file on the singer.