Actor Philip Seymour Hoffman's cause of death has been revealed.

The Oscar winner was found dead in his Manhattan apartment, with a needle stuck in his arm, on Feb. 2.

Hoffman died of acute mixed drug intoxication, according to the NYC medical examiner's office, as reported by PEOPLE. Traces of heroin, cocaine, benzodiazepines and amphetamine were all found in his system. The first autopsy, performed earlier this month, proved inconclusive.

His death was ruled an accident.

Hoffman had dealt addiction for most of his life and checked into rehab last May to battle a heroin addiction despite 20 years of sobriety. He was almost done filming 'The Hunger Games: Mockingjay' at the time of his death.

Hoffman, who took home the Academy Award for Best Actor for his work as Truman Capote in 'Capote,' and who had memorable roles in 'Boogie Nights,' 'Magnolia' and 'Almost Famous,' was just 46.

He leaves behind three children and a revered legacy of film work.