Embattled rapper Chief Keef has walked free from an Illinois jail after serving less than half of a 20-day sentence for a failed drug test.

The rising teen star, real name Keith Cozart, began his bid behind bars on 15 October (13) after breaking the terms of his probation by testing positive for marijuana.

However, he was released from Cook County Jail on Wednesday (23Oct13), 11 days early, after receiving credit for good behaviour, reports the Chicago Sun-Times.

Keef's probation related to a May (13) arrest for speeding, for which he pleaded guilty and was ordered to undergo random drug tests as part of his sentencing.

It was the 18 year old's latest run-in with the law - he already has a 2011 firearms conviction on his record, while he is currently facing two claims for child support from two different women.