Redmond O'Neal

Redmond O'Neal has been sent back to jail after a drug-related probation violation.

He appeared Tuesday in a Los Angeles courtroom, where a judge ordered him to complete a 30-day in-custody drug treatment, Jane Robison, a Los Angeles County district attorney's spokeswoman, told TVGuide.com.

The troubled 24-year-old son of Ryan O'Neal and the late Farrah Fawcett must remain in jail throughout the duration of the drug treatment, which began immediately.

Redmond O'Neal to leave jail, ordered to rehab

O'Neal was arrested Dec. 29 for allegedly violating his probation, although the details about O'Neal's arrest were not disclosed. He had been undergoing in-patient rehab before his arrest.

Most recently, O'Neal was charged with bringing narcotics to a jail and possessing a controlled substance in April 2009. Seven months earlier, he and his father were arrested for suspected drug possession and Redmond was ordered to attend a two-week treatment program. At the time of his and his father's arrests, Redmond was on three year's probation for DUI and drug possession.

O'Neal was behind bars during his mother's final days. He was allowed to visit her shortly before her June 25 death and to attend the Charlie's Angels actress' funeral.

He is next due in court Feb. 2.