In 1997, the 34-year-old star of the hit movie Chaplin was locked up for violating his probation on a 1996 drug conviction.

This time, a municipal court judge in Malibu, California, ordered that Downey be sent to a secure drug treatment centre after he admitted to failing to take periodic court-ordered drug tests since December.

Downey was nominated for an Oscar for Chaplin

He also said that he was finding kicking his addiction hard: "I'm coming here with my drug counsellor to tell you that I still find (staying clean) difficult," he told Judge Lawrence Mira.

The judge also ordered Downey to have intensive psychiatric treatment while in jail before returning to court on 5 August.

The admission comes after a series of arrests, failed rehabilitation efforts and second chances for the actor, who was nominated for an Oscar for his physically demanding title role in Chaplin in 1992.

Nonetheless, outside the court his attorney, Peter Knecht, praised his client and said that he very much wanted to go for the Impact (drug treatment) to get better.

"He feels that will be the best thing for him, and it is a very brave, courageous move to do that. He's a wonderful man. He's a very talented man and he'll be back on his feet real quick," he said.

In court on drugs and firearms charges in 1996

In 1997, the actor spent 113 days in jail for breaking his probation on a 1996 drug conviction in which he admitted using an illegal drug.

He was arrested three times in 1996, once was for driving while intoxicated and carrying heroin, cocaine and an unloaded gun in his pick-up truck.

Prior to this setback, he had been working on four films including the Mike Figgis-directed One Night Stand starring Natassja Kinksi and Wesley Snipes.

He was also allowed to complete filming on DreamWorks SKG's serial-killer thriller In Dreams during his incarceration.

He also reportedly dropped out of a recent NBC TV series, God, the Devil and Bob, when he failed to show up for rehearsals.

In this latest court appearance, the judge could have sentenced Downey to three years in prison for violating probation.

Instead, he will stay on the lock-down drug treatment programme until at least 5 August when he returns to court for a progress hearing.