Image copyright AFP

Singer Chris Brown will serve an additional 131 days in jail after admitting to violating his probation.

The R&B star admitted to a court in Los Angeles on Friday that he committed a crime in Washington DC last October.

The Los Angeles judge sentenced Brown to 365 days but gave him credit for 234 days he has spent in rehab and jail.

Brown has been under court supervision since 2009 when he pleaded guilty to assaulting pop singer Rihanna, who was his girlfriend at the time.

The Grammy winner has been in custody since March, when he was arrested over alleged violations of his rehab sentence.

His latest probation violation relates to an altercation in the nation's capital last year.

Brown faces a misdemeanour assault charge after a man accused the singer of punching him outside a Washington hotel.