NEW YORK -- An unidentified patron of a Midtown S&M club who was bound and suspended from a ceiling while wearing women's high heels and a neck choker was hospitalized in critical condition Friday, police sources said.

While an accident is the most likely cause, police said they are investigating whether he was the victim of a crime. Officials said a preliminary check showed that the club is a legal business.

One law enforcement source said this incident appeared to be an accident because the man apparently had consented to the treatment. Due to the seriousness of his injuries, police started an investigation, said an NYPD spokesman.

"Detectives are investigating whether there is any criminal culpability with the operators," said a police spokesman.

The man was found about 1:30 a.m. inside the East 33rd Street club known as Nutcracker Suite and Artistic Innovation, wearing his pants but not carrying any identification, police said.

He's listed in critical condition at St. Vincent's Medical Center, said police sources.

Detectives are trying to determine how long the man was left alone once tied up, sources said. He was discovered in apparent respiratory distress after a club worker checked on him as he was suspended from the ceiling and noticed that his hands looked blue, a police source said.

Attempts to reach the club were not successful.

The law enforcement source said that the club's staffers were cooperating with the police and told investigators that they had checked on the man in regular intervals after he had been bound and suspended.