Actor Philip Seymour Hoffman, who was found dead in his New York apartment on Feb. 2 with a needle in his arm, died of an accidental overdose of drugs, the New York City Chief Medical Examiner said on Friday.

The cause of death was acute drug intoxication, including heroin, cocaine, benzodiazepines and amphetamine, according to Julie Bolcer, spokeswoman for the Medical Examiner's Office.

No other details were immediately available.

A drug overdose had been suspected when Hoffman, 46, was discovered.

Heroin not cut with dangerous additive

Investigators have been probing how Hoffman may have obtained the heroin. Tests of the heroin in his apartment have found that it was not cut with a dangerous additive such as fentanyl, a synthetic form of morphine used to intensify the high that has been linked to deaths in other states.

A musician, veteran jazz player Robert Vineberg, has been charged with keeping a heroin stash in a lower Manhattan apartment amid the investigation into Hoffman's death. Vineberg, who has said he was a friend of  Hoffman, hasn't been charged in Hoffman's death and has said he didn't sell him the heroin found in his apartment.

As police followed a tip after Hoffman's death, they said they found about 300 small bags of heroin, worth about $10 apiece on the street, and $1,300 in cash in Vineberg's apartment and music studio.

The confirmation of Hoffman's cause of death puts the actor, regarded as one of the best of his generation, on a growing list of entertainers who succumbed to drugs.

Glee actor Cory Monteith, 31, died in Vancouver of an accidental overdose of heroin and alcohol in July. Drugs were also the cause of death of Australian actor Heath Ledger in 2008 and singer Whitney Houston in 2012.

Hoffman's tragic death coincides with an increase in U.S. heroin use, which government officials say has reached epidemic proportions during the past five years.

Hoffman, a best actor Oscar winner for his role in the 2005 biographical film Capote, won accolades for his versatility and mesmerizing performances on the stage and screen.

With files from The Associated Press