Police found a crack pipe and prescription pills in the Manhattan apartment, said a law enforcement official, who spoke to The Associated Press on condition of anonymity because the investigation was ongoing. Paramedics had to break down the door before they found him, shirtless and wearing sweatpants, in his bed around 5:20 p.m. on Friday, the official said.
A friend had called police to say he was unable to get into the home in the trendy SoHo neighborhood. There was no evidence of foul play, and a medical examiner will determine the cause of death.
Last year, he was badly hurt in a South Carolina plane crash that killed four people and seriously injured rock musician Travis Barker.

DJ AM, whose real name was Adam Goldstein, had openly discussed past addictions to crack cocaine, Ecstasy and other drugs, addictions so bad he once tried to commit suicide by shooting himself in the head
- but the gun jammed. However, he claimed he had been drug-free for years, even swearing off cigarettes.
His spokeswoman, Jenni Weinman, said the circumstances surrounding his death were unclear. She pleaded for privacy for his family.
In October, MTV was to debut his reality show, "Gone Too Far," in which he and concerned families staged interventions for drug abusers. In a recent AP interview, he talked about holding a crack pipe for the first time in years for the show and said he felt as though he had an angel on his shoulder for surviving so much turmoil.
"There's no better way to remember what it was like when I was at my bottom than to see someone at their bottom," he told the AP.
MTV did not have an immediate comment on whether Goldstein's show would air, but said in a statement that it "was honored to support him as he helped young people battle their own addictions."
Goldstein was a deejay for hire who performed at Hollywood's most exclusive parties and was admired by music aficionados. He also was famous for relationships with reality TV star Nicole Richie, the daughter of singer Lionel Richie, and with actress-singer Mandy Moore.
Goldstein was critically injured last September when a Learjet crashed on takeoff in Columbia, S.C. The plane was transporting Goldstein and Barker, a drummer for the pop punk band Blink-182, after a performance; the pair had formed the duo TRVSDJ-AM.
Barker and Goldstein were burned, though Barker was injured more severely. Goldstein had to get skin graft surgery, but about a month later he was performing again, joining Jay-Z on stage.
At the time, he told People magazine he was grateful to survive.
"I can't believe I made it," he said. "I've prayed every night for the past 10 years. There's a lot more to thank God for now. ... I was saved for a reason. Maybe I'm going to help someone else. I don't question it. All I know is I'm thankful to be here."
Goldstein rose to fame several years ago as highly sought-after DJ whose beats kept the dance floor packed and clubgoers hypnotized. He was known for his deft mashups, a blend of at least two songs, and performed not only in clubs but on grand stages, appearing earlier this year at the Coachella music festival in Indio, Calif.