Iron Man legend actor Robert Downey Jr.’s son has been arrested for suspicion of cocaine possession.

Indio Falconer Downey was taken into custody yesterday after a car he was driving was pulled over in West Hollywood, California, authorities said.

Downey Jr. thanked the police for arresting his son and said the family was determined to get him the help he needs.

“Unfortunately, there’s a genetic component to addiction and Indio has likely inherited it,” Robert Downey, Jr., who had a series of high-profile drug-related arrests in the late 1990s, said in a statement.

“We’re grateful to the Sheriff’s Department for their intervention, and believe Indio can be another recovery success story instead of a cautionary tale.”

Downey Jr’s drug use sent him to prison and rehab and cost him many acting roles.

He is now one of the industry’s most bankable stars after appearing in Marvel’s Iron Man trilogy and The Avengers.

Indio Downey was booked on suspicion of possession of a controlled substance, believed to be cocaine, and possession of drug paraphernalia, sheriff’s Sgt. Dave Valentine said.

He was later released after posting $US10,250 bail. A court date was set for August 29.

Two other people were in the car, but only Downey was arrested.

He appeared in the 2005 movie Kiss Kiss Bang Bang, which starred his father.