Scott Ruffalo - who was found in his Beverly Hills apartment with a gunshot wound to his head last December - tested positive for cocaine, alcohol and morphine.
Los Angeles County Coroner spokesman Ed Winter confirmed: "Ruffalo's toxicology results showed a very slight trace of cocaine and alcohol. He also had slight traces of morphine which could have been due to prescription medication.
"All we can conclude from this is that he was not under the influence of drugs when he was shot due to the small amount." Winter added coroners maintain Scott's death was a homicide. Scott, 39, died in hospital a week after he was discovered at his apartment.
Shaha Mishaal Adham turned herself into police in connection with the shooting after she was named as a "person of interest" by police because she was on the surveillance video at the Scott's home. Adham admitted leaving the scene following the death after collecting a set of car keys. She was later cleared of all charges.
She claims Scott's death was a result of a game of Russian roulette, and her lawyer Ronald Richards has disputed the coroner's verdict. Richards said at the time: "The only two eye witnesses to the shooting saw the same thing, a gunshot wound to the left side of the head, while one of them saw him pull the trigger. "They saw the gun in his left hand after the shot was fired."