AceShowbiz -

This just in. Nicole Richie has begun serving her 90-days jail sentence for driving under the influence of drugs, but was released after only 82 minutes.

The pregnant socialite checked into Los Angeles jail at 3:15 p.m. on Thursday August 23rd accompanied by boyfriend Joel Madden and her lawyer Shawn Chapman Holley. She was then released at 4:37 p.m. "based on her sentence and federal guidelines," Los Angeles County Sheriff's Deputy Maribel Rizo said in a statement.

Refused to elaborate on Nicole's brief jail sentence, Rizo simply said the reality TV star was "treated in the same manner as other inmates with a similar sentence," and that she was "was highly cooperative."

Nicole was pleaded guilty to driving under the influence (DUI) and thus sentenced to four days or 96 hours in jail back on July 27th, fined $2,048 and placed on three-years probation. The sentence was later on reduced to 90 hours because of time served when she was arrested.

Nicole was arrested early on Dec. 11th after witnesses reported seeing her black Mercedes-Benz sport utility vehicle headed the wrong way on a freeway in Burbank. The California Highway Patrol said they found her parked in the car pool lane. She is said to have told authorities she had smoked marijuana and taken the prescription painkiller Vicodin. No drugs were found on her or in the car.