Millionaire and convicted sex offender Jeffrey Epstein put on suicide watch after being found injured in jail: Source Millionaire Jeffrey Epstein was found in his jail cell with neck injuries.

Millionaire and convicted sex offender Jeffrey Epstein, facing charges of federal sex trafficking, was placed on suicide watch after being found unresponsive and with injuries to his neck at a federal lockup in New York City, according to a law enforcement official briefed on the incident.

Epstein, 66, was discovered injured on Tuesday in his cell at the Metropolitan Correctional Center in Manhattan, where he is being held without bail, the source said.

He was discovered with marks on his neck that appeared to be self-inflicted, the source said.

He was medically evaluated before being returned to his jail cell and placed on suicide watch, according to a source with knowledge of the incident.

The Bureau of Prisons, which oversees the Metropolitan Correction Center, is investigating the incident as a possible suicide attempt, the source said.

"Jeffrey Epstein is currently housed at MCC New York and not in a local hospital as has been reported," the Bureau of Prisons said in a statement released Thursday. "As with all inmates, for privacy and security reasons, we do not share information on an inmate's medical status or their conditions of confinement."

Officials at the U.S. Attorney’s office for the Southern District of New York, which is prosecuting Epstein’s sex trafficking case, had no comment.

The incident came five days after U.S. District Court Judge Richard Berman denied a request from Epstein's attorney that he be released on bail, pending his trial.

Berman made the decision over the objections of defense attorneys who had argued that Epstein was a “disciplined” defendant willing to pay a bond of $100 million or more.

The judge also noted that during a search of Epstein’s Manhattan mansion, authorities found $70,000 in cash, an assortment of diamonds, and an expired Austrian passport with Epstein’s photo but not his name in a locked safe.

Epstein has pleaded not guilty to charges of sexually exploiting and abusing dozens of minor girls. He faces up to 45 years in prison if convicted.

The hedge fund manager -- who at one time socialized with former President Bill Clinton, Great Britain's Prince Andrew, and President Donald Trump -- was arrested on July 6 for alleged sex trafficking of minor girls in Florida and New York. Some of the charges date back to the early 2000s.

A team of law enforcement officers from the Federal Bureau of Investigation (FBI) and the New York Police Department (NYPD) took Epstein into custody at the Teterboro Airport in Bergen County, New Jersey, after he returned to the United States by private jet from France, sources told ABC News.

In 2008, Epstein pleaded guilty to soliciting prostitution in a secret plea deal with federal prosecutors in Palm Beach, Florida, to avoid more serious federal sex trafficking charges. He received a 13-month jail sentence but was allowed out for work release 12 hours a day, six days a week. The deal, now under review by the Justice Department’s Office of Professional Responsibility, also gave Epstein and any alleged co-conspirators immunity from further federal prosecution in the Southern District of Florida.