The official, who declined to be named, told AFP the cause of death was under investigation.
Police responded to the scene in Manhattan's West Village after receiving a call at about 11:15 a.m., the official said.
The New York Post is reporting that the actor, 46, was found dead with a needle in his arm, the result of an apparent overdose.
The Post reports:
Hoffman, 46, publicly admitted in 2006 that he nearly succumbed to substance abuse after graduating from NYU’s drama school, but got sober in rehab.
“It was all that [drugs and alcohol], yeah. It was anything I could get my hands on…I liked it all,” he told “60 Minutes” as the time.
Last year, Hoffman reportedly checked himself into rehab again after relapsing in 2012.
The Wall Street Journal reports that the actor was found in the bathroom of his fourth floor apartment in the Pickwick House by a screenwriter, who called 911.