Philip Seymour Hoffman died from accidental drug overdose

Philip Seymour Hoffman died from an accidental drug overdose, an official report from the New York Medical Examiner's office said Friday.

The 46-year-old Oscar-winner died Feb. 2 in his New York City apartment from a fatal combination of prescription drugs. He was found lying in his bathroom with a needle still in his arm.

The Medical Examiner's office conducted more toxicology and tissue tests after initial autopsy results were inconclusive. Spokeswoman Julie Bolcer said that heroin, cocaine, amphetamines and benzodiazepines for anti-anxiety caused Hoffman's death, the Democrat and Chronicle reported.

Dr. Sanjay Gupta, CNN's chief medical correspondent, said that taking a lethal mixture of drugs more frequently can cause someone to build a high tolerance.

"They're not feeling it, but it's still having an impact on their ability to breathe, and that's the real problem," he said according to CNN. "It's called stacking. You can stack the same drug too close together, or you can start to stack other drugs, one on top of the other. That's how people get into trouble. They do call it accidental death as well."

All knew Hoffman's struggle with drug abuse in the past, and after 23 years of sobriety he had checked into rehab in 2013 after a heroin relapse.

He had three children with estranged girlfriend, costume designer Mimi O'Donnell. His estate will be left to O'Donnell, and his eldest son - his only child at the time he drafted his will - will grow up in New York City among the art and culture, per his wishes.

Family, friends and fellow actors mourned Hoffman at his funeral held Feb. 7 in Manhattan.

The renowned actor grabbed a 2006 Oscar for his lead role in "Capote," and was also nominated for his supporting roles in "Charlie Wilson's War" (2007), "Doubt" (2008) and "The Master" (2012).

Hoffman is more recently known for his portrayal of gamemaker Plutarch Heavensbee in the blockbuster hit "The Hunger Games: Catching Fire." He had been filming "The Hunger Games: Mockingjay Part 2" (Part 1, out Nov. 21), but was largely finished at the time of his death, with only seven days left to shoot. Distributor Lionsgate states that its Nov. 20 release date is still on schedule.