NEW YORK — Guards on Jeffrey Epstein's unit were working extreme overtime shifts to make up for staffing shortages the morning of his apparent suicide, a person familiar with the jail's operations told The Associated Press.

The person said that the Metropolitan Correctional Center's Special Housing Unit was staffed with one guard working a fifth straight day of overtime and another who was working mandatory overtime. The person wasn't authorized to discuss jail operations publicly and spoke Sunday on the condition of anonymity.

The jail staff failed to follow protocols leading up to Epstein's death, according to a report from The New York Times, deepening the fallout from what led to the highly connected financier's apparent suicide.

Epstein should have been checked on by guards in his cell every 30 minutes, but that didn't happen the night before his apparent suicide, a law enforcement official told the Times.

The mystery surrounding how Epstein was able to kill himself in jail comes as investigators have been digging into allegations of sexual abuse and conspiracy against him.

An additional federal investigation was launched Saturday after the Federal Bureau of Prisons said Epstein was found unresponsive in his cell at a high-security jail in Manhattan. He was later pronounced dead from an apparent suicide, the bureau said. His abrupt death cuts short a criminal prosecution that could have pulled back the curtain on the inner workings of the high-flying financier with connections to celebrities and presidents, though prosecutors have vowed to continue investigating.