Billionaire Jeffrey Epstein in Cambridge, MA on 9/8/04. Epstein is connected with several prominent people including politicians, actors and academics.

Rick Friedman | Corbis News | Getty Images

Jeffrey Epstein, the disgraced financier who hung himself in his Manhattan jail cell, was left alone and not monitored by guards who were supposed to check on him every 30 minutes, a law-enforcement official with knowledge of his detention told The New York Times.

Epstein’s cell mate had been transferred out at the time of Epstein’s suicide, the Times reported, leaving him alone only two weeks after he was taken off suicide watch, a move that also violated the Metropolitan Correctional Center’s standard protocol, according to officials. Epstein had been found unconscious in his cell on July 23, with marks around his neck.

As the Justice Department and FBI investigate Epstein’s death, the Federal Bureau of Prisons is under intense scrutiny for not keeping Epstein on suicide watch after his first apparent suicide attempt.

It’s standard procedure for guards in the special housing units to look inside inmates’ cells every 30 minutes, so it’s unclear why Epstein wasn’t checked on.

Like other federal prisons, the Metropolitan Correctional Center has been short staffed for some time. The two guards on duty where Epstein stayed were both working overtime, one of whom was on his fifth day straight of overtime, an official told The Times.

Epstein’s death has led to a slew of conspiracy theories spreading across the internet, some of which suggest, without evidence, that Epstein was killed in order to protect others in his circle who could also be incriminated.

Epstein, a one-time friend of Bill Clinton and Donald Trump, was accused of sexually exploiting and trafficking dozens of underage girls. He pleaded not guilty to the charges, and faced a maximum sentence of 45 years in prison if convicted.

He was found dead in his jail cell at 6:30 a.m. on Saturday. It was just a day after a federal appeals court unsealed nearly 2,000 pages of documents revealing new information on how he lured underage girls into prostitution, and payed them to provide erotic massages in his various mansions.