04/21/2004 at 01:00 AM EDT
Robert Downey Jr. was arrested in suburban Los Angeles on Tuesday on charges of being under the influence of a controlled substance, police said. Downey, 36, was taken into custody just after midnight Tuesday morning in Culver City and detained for a few hours, according to a police spokesman. The spokesman did not reveal further details about the incident or disclose the name of the substance Downey was accused of taking. The actor was ultimately released to the custody of his parole agent and ordered to return for a court hearing. The troubled actor, who in January won a Golden Globe for his work on "Ally McBeal," spent a year in a California prison on drug-related charges. Three months after his August 2000 release, he was arrested for drug possession and being under the influence of a controlled substance in Palm Springs, Calif. If convicted on all three counts in the case (felony possession of cocaine, felony possession of the prescription sedative diazepam, also known as Valium, and a misdemeanor count of being under the influence of a controlled substance), he could be looking at a maximum sentence of four years and eight months in state prison. (Downey's brushes with the law hark back to 1996, when Los Angeles police stopped him for speeding and then found cocaine, heroin and a gun in his car.) In December 2000, Downey's stepmother, Rosemary Rogers Downey, told PEOPLE that the actor was diagnosed with bipolar disorder syndrome and has not received help for it. "It's the reason he has a hard time staying sober," she says. "What hasn't been tried is medication and intensive psychotherapy."