Alig's death late Thursday or early Friday (US time) is being investigated as a possible drug overdose, police said.
The investigation into his death is still ongoing.
No official cause had been determined, Aja Worthy-Davis, a spokesperson for the New York City medical examiner's office, said Saturday.
Alig was part of a decadent 1990s party scene characterized by wild costumes and rampant drug use. He pleaded guilty to manslaughter in 1997 for killing Andre "Angel" Melendez.
Alig admitted that he and Robert "Freeze" Riggs killed Melendez, cut the body up and dumped the parts in the Hudson River.
Amanda Lepore and Michael Alig at Club US in New York during 1993. Photo / Getty Images
Riggs also pleaded guilty to manslaughter. He was released in 2010.
At the time of his release, the promoter told The Guardian that his sentence helped him face what he had done to his friend.
"It takes going to prison for 17 years and going through extensive therapy, then having to face what you are and how you behaved," Alig explained to The Guardian.
"Because while you're on drugs, you're not facing anything" he said.
Despite being on drugs, Alig told The Guardian that he took full responsibility of his actions.
"I was responsible because I made the decision to do drugs," he said.
"And when I made that decision I wasn't on drugs."
The story was turned into the 2003 movie "Party Monster," in which Macaulay Culkin played Alig.
Michael Alig(left) was the first to establish Club Kids, a group of young New York City dance club personalities. Photo / Getty Images
Alig maintained a social media presence while behind bars, although he had no access to a computer and dictated tweets to a friend over the prison phone.
