Actor Robert Downey Jr. blamed himself Monday for his son’s drug bust, saying he must have passed on genes prone to substance abuse and addiction.

Indio Falconer Downey, 20, was arrested Sunday in Southern California, reportedly for possession of cocaine.

“Iron Man” star Robert Downey Jr. famously battled drugs for much of the 1990s before cleaning up and becoming one of Tinseltown’s biggest stars.

“Unfortunately there’s a genetic component to addiction and Indio has likely inherited it,” the concerned  dad said in prepared statement.

“Also, there is a lot of family support and understanding, and we’re all determined to rally behind him and help him become the man he’s capable of being. “

The “Sherlock Holmes” actor  actor even thanked law enforcement for coming down on Indio.

“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,” Robert Downey Jr. said.

Los Angeles County sheriff’s deputies rolled up next to a car with Indio inside and spotted him “apparently using the pipe,”  smoking cocaine, Los Angeles County Sheriff’s Sgt. Dave Valentine told the LA Times.

The car was pulled over near Santa Monica and La Cienega boulevards in West Hollywood at about 2 p.m., before Indio was allegedly found with cocaine, officials said.

The actor’s was booked into jail for possession of a controlled substance and released on $10,250 bail at 12:19 a.m. Monday,  Sgt. Harry Drucker said.

Indio, whose mother is Robert Downey Jr.’s first wife, Deborah Falconer, has battled substance abuse before and did a stint in rehab last year, the National Enquirer reported then.