New York (CNN) -- New York police have taken in for questioning four people who are believed to be connected to the drugs found in late actor Philip Seymour Hoffman's apartment, a New York law enforcement official told CNN Tuesday night.
No additional information was released.
When police were called to Hoffman's fourth-floor Manhattan apartment Sunday, they found the actor lying on the bathroom floor with a syringe in his left arm. He was wearing shorts and a T-shirt, his eyeglasses still resting on his head, according to law enforcement sources familiar with the inquiry.
Investigators discovered close to 50 envelopes of what they believed was heroin in the apartment, the law enforcement sources said. They also found used syringes, prescription drugs and empty bags that authorities suspect are used to hold heroin, the sources told CNN.
Also Tuesday, preliminary tests showed the heroin recovered from the apartment does not contain fentanyl, a law enforcement official told CNN.
More testing will be done, but as of now no fentanyl has been detected.
Fentanyl is a powerful narcotic used to treat cancer patients' pain.
Last week, Maryland officials said that heroin tainted with fentanyl had claimed at least 37 lives since September. And last month, at least 22 people in western Pennsylvania died after using heroin that had been mixed with fentanyl.