Authorities are working to determine what caused the death of Oscar-winning actor Philip Seymour Hoffman, who is believed to have suffered an accidental drug overdose.
An autopsy began Monday, but results weren't expected until at least Tuesday, the New York City medical examiner's office said.
Hoffman, 46, was found dead Sunday in his Greenwich Village apartment with what law enforcement officials said was a syringe in his arm.
The two officials told The Associated Press that glassine envelopes containing what was believed to be heroin were also found with Hoffman (TMZ is reporting that approximately 50 heroin bags were found in the apartment). Those items are being tested.
The law enforcement officials, who spoke to The Associated Press on condition of anonymity because they are not authorized to speak about evidence found at the scene, said the cause of death was believed to be a drug overdose. Police will only say the investigation is continuing.
Hoffman spoke candidly over the years about past struggles with drug addiction. After 23 years sober, he admitted in interviews last year to falling off the wagon and developing a heroin problem that led to a stint in rehab.
The law enforcement officials said Hoffman's body was discovered in a bathroom at his apartment by a friend who made the 911 call and his assistant.
Late Sunday, crime-scene technicians carrying brown paper bags went in and out of Hoffman's building as officers held back a growing crowd of onlookers.
Hoffman's family called the news "tragic and sudden."
"We are devastated by the loss of our beloved Phil and appreciate the outpouring of love and support we have received from everyone," the family said in a statement.
He is survived by his partner of 15 years, Mimi O'Donnell, and their three children.