A judge warned troubled US starlet Lindsay Lohan that she faces jail, as she appeared in court again over the theft of a $2,500 necklace from a Los Angeles jewellery store.

Judge Keith Schwarz told the 24-year-old that she would be sent to jail if she pleads guilty under a deal offered by prosecutors, connected with an earlier probation violation.

“This case does involve jail time – period,” he said. “If you plead in front of me – if this case resolves in front of me – you are going to jail. Period. It may be an issue as to amount of time.”

The actress, who could have been ordered back into detention immediately, was told to appear in court again on March 10 over the alleged theft in January near her home.

She could ask for a trial instead of pleading guilty.

Dressed in a black top and ivory-coloured pants, she sat quietly and conferred with her lawyer during the brief hearing, and afterwards left without saying anything to waiting reporters.

Ms Lohan, who completed a court-ordered spell in rehab for drug addiction last month, allegedly walked out of the jewellery store in Venice Beach – the seafront area of LA where she lives – with the gold necklace on January 22.

The actress, who is on probation for a 2007 drunk driving offence, could face up to three years in jail if convicted on the grand theft charge. She pleaded not guilty in a first appearance on February 9.

She checked out of the Betty Ford clinic near Palm Springs last month, following a spell there after she was briefly jailed in September for failing a court-ordered drug test.