Embattled R&B star Chris Brown has been granted permission to leave his lockdown rehab centre in California for a few hours on Sunday (22Dec13) to co-host a charity toy drive.

The Kiss Kiss hitmaker is currently enrolled in a court-ordered 90-day anger management treatment programme, but he will honour a scheduled appearance at this weekend's Xmas Toy Drive, organised by bosses at the Brooklyn Projects skateboard firm and Brown's clothing company, Black Pyramid.

His on/off girlfriend Karreuche Tran, who has helped create items for Black Pyramid, will also attend the Los Angeles event and collect unwrapped gifts for underprivileged kids, reports Tmz.com.

Brown was ordered to seek help for his temper troubles last month (Nov13) after the judge overseeing his probation learned that he had been kicked out of another rehab centre in Malibu for allegedly hurling a rock through his mother's car window.

The singer, who was placed on supervised release for his 2009 attack on then-girlfriend Rihanna, has since had his probation revoked after the judge ruled on Monday (16Dec13) that a misdemeanour assault charge relating to a recent fight in Washington, D.C. violated the terms of his freedom. He has pleaded not guilty to the count.

The court official refused to have Brown taken into custody in favour of the star continuing his anger management treatment, although he must return for another progress update in February (14).