Robert Downey Jr., who is already facing drug charges, has been arrested again for allegedly being under the influence of a controlled substance.
Police say the actor was picked up shortly after midnight while walking on Washington Boulevard in Culver City, Calif.
Downey was detained for a few hours, issued a citation and released to his parole officer. The actor must appear in court on May 4.
Shortly after his release, he voluntarily checked himself into a rehabilitation facility.
"Obviously he is working hard at his sobriety and his rehabilitation. He's in charge of his own destiny," Downey spokesman Alan Nierob told The Associated Press.
The actor, who currently appears in Ally McBeal, has had several brushes with the law over drug use. His lawyers are currently challenging the legality of a hotel room search last fall that led to his arrest on drug possession charges. Police say they found cocaine and Valium in the room.
He is expected to appear in court Monday in San Bernadino on those charges, and could face jail time if convicted.
Downey had been scheduled to do an in-store appearance today at a record store in Los Angeles with singer Vonda Shepard to promote a soundtrack album from Ally McBeal. On the album, Downey does a duet with Sting of "Every Breath You Take." Downey also sings a song that he wrote called "Snakes."
"I think he may get a record deal after this, when this record comes out," Shepard said prior to the arrest. "He's got soul."
Long History of Legal Trouble
Downey's legal troubles date to June 1996, when he was stopped for speeding on the Pacific Coast Highway and authorities found cocaine, heroin and a pistol in his vehicle.
A month later, he was found passed out on a child's bed in a neighbor's home. Three days later, he was arrested after leaving a recovery center. He was jailed in August 1999 after he admitted during a probation hearing that he was missing scheduled drug tests. Superior Court Judge Lawrence Mira sentenced him to three years in prison for violating his probation.
Downey had established an impressive movie career before his incarceration. The son of film director Robert Downey, he earned an Oscar nomination for his work in the title role in Chaplin, the 1992 screen biography of famed comedian Charlie Chaplin. He won a Golden Globe for his work on Ally McBeal and recently appeared in Wonder Boys.
Other film credits include Less Than Zero, Natural Born Killers, One Night Stand and Two Girls and a Guy.
ABCNEWS Radio contributed to this report.