Jeffrey Epstein was found unconscious in a Manhattan jail cell with injuries to his neck, media reported, citing unidentified sources.
Epstein was found by guards sprawled on the floor of cell at the Metropolitan Correctional Center, media reported. Some media reported that his face appeared blue.
The financier was taken to hospital, the New York Post reported, but it was unclear where he was taken or what his condition was.
It was not clear how he suffered his injuries.
Neither a representative for the correctional center nor Epstein's attorney returned calls or email inquiries from Reuters.
Epstein was recently denied bail, a move his lawyers plan to appeal according to a court notice made public on Tuesday.
Epstein was expected to ask the 2nd US Circuit Court of Appeals to overturn the judge's 18 July rejection of his request to remain under house arrest in his $US77 million ($NZ114.9m) mansion on Manhattan's Upper East Side.
Epstein has pleaded not guilty to the charges and the appeal for bail was expected. His lawyer Reid Weingarten did not immediately respond to requests for comment. A spokesman for US Attorney Geoffrey Berman in Manhattan declined to comment.
The charges, concerning alleged misconduct from at least 2002 to 2005, were announced more than a decade after Epstein pleaded guilty to state prostitution charges in Florida.
In denying him bail, US District Judge Richard Berman in Manhattan said the government had shown by clear and convincing evidence that Epstein would pose a danger to the community if released pending trial.
-Reuters