Jeffrey Epstein was found hanging in his lower Manhattan jail cell with a bedsheet wrapped around his neck and secured to the top of a bunk bed, The Post has learned.

The convicted pedophile, who was 6 feet tall, apparently killed himself by kneeling toward the floor and strangling himself with the makeshift noose, law enforcement sources said Monday. He hadn’t been checked on for several hours, sources said.

Epstein was “unresponsive” when he was discovered in his cell at the Special Housing Unit of the Metropolitan Correctional Center at around 6:30 a.m. on Saturday, the federal Bureau of Prisons has said.

Staffers attempted to revive him and he was taken to an infirmary inside the lockup, then transported by ambulance to the NewYork-Presbyterian Lower Manhattan Hospital, where he was pronounced dead.

The FBI and the Justice Department are both investigating the incident, which US Attorney General William Barr on Monday blamed on “serious irregularities at this facility.”

Barr vowed that authorities would “get to the bottom of what happened,” saying the case against Epstein was “very important to the Department of Justice and to me personally.”

“Most importantly, this case was important to the victims who had the courage to come forward and deserved the opportunity to confront the accused in the courtroom,” Barr said during the keynote address to the biennial conference of the Fraternal Order of Police in New Orleans.

One of the two workers who were assigned to guard Epstein in the 9 South unit wasn’t even a full-fledged federal correction officer, The New York Times reported early Monday evening.

Prison officials with knowledge of the case said that only one of the people normally worked as a correction officer but didn’t say what sort of job the other employee usually worked, according to the Times.

On Sunday, reports said the two workers were both on overtime, with one on his fifth straight day of extra hours and the other forced to work overtime that day.

Epstein was taken off a 24-hour suicide watch — which required a check every 15 minutes — following a July 23 incident in which he was found with marks on his neck.

He had been downgraded to “special observation status,” which required two guards to make separate checks on him every 30 minutes, but that procedure was not followed, a source has told Reuters.

Under that status, Epstein also was supposed to have a cellmate, but that inmate apparently left — possibly for a court appearance or another appointment — and was not immediately replaced as required by protocol, the Wall Street Journal reported.

Epstein was removed from suicide watch at the request of his defense lawyers, who had been meeting with him for up to 12 hours a day before asking that his supervision be eased, the Journal said.

The decision to remove an inmate from suicide watch would normally have to be approved by the prison’s suicide prevention program coordinator and also by its warden, according to NBC News, which cited protocols.

“Once an inmate has been placed on watch, the watch may not be terminated, under any circumstance, without the program coordinator or designee performing a face-to-face evaluation,” according to guidelines issued by the Bureau of Prisons in 2007.

One of Epstein’s lawyers, Marc Fernich, declined to comment, citing the federal probes into his client’s death.