Philip Seymour Hoffman died of acute mixed drug intoxication, including heroin, cocaine, benzodiazepines and amphetamine, the New York City chief medical examiner’s office has determined.

The death was ruled an accident.

Police had been investigating his death as a suspected drug overdose.

Law enforcement officials have said Hoffman was found Feb. 2 with a needle in his arm, and tests found heroin in samples from at least 50 packets in his Manhattan apartment.

The 46-year-old star of “Capote” and “The Master” said in interviews last year that he had sought treatment for a heroin problem after 23 years of sobriety.

The Associated Press contributed to this report.