At least one camera stationed in the hallway outside billionaire financier and convicted sex offender Jeffrey Epstein's prison cell, where officials say he hanged himself earlier this month, had footage that was deemed unusable, The Washington Post reports.

While one hallway camera had unusable footage, another nearby camera caught clearer video, the Post noted, adding that it is unknown why certain footage was useable while some was not, as well as the extent of the glitch.

Epstein's death in federal custody as he awaited trial on sex trafficking and abuse charges raised a series of questions. He was jailed at the Metropolitan Correctional Center in Manhattan, where New York City's chief medical examiner later determined he killed himself.

Attorney General William Barr said he was "appalled" and "angry" over the circumstances surrounding Epstein's death and directed the FBI and the Justice Department inspector general to investigate it. Officials plan to use the footage recorded in determining whether protocol was violated or laws were broken.

Lawmakers have continued to demand answers about why Epstein - who had high-profile friends and acquaintances including President Trump and former President Clinton - was not being more closely observed and whether he should have been on suicide watch after initially being placed on watch in July, when he was found with marks on his neck. Epstein was reportedly removed from suicide watch that same month after being cleared by a psychologist.

Reports have surfaced that show abnormalities in how he was observed, including one saying guards in Epstein's unit fell asleep and failed to check on him for roughly three hours during the time when he is believed to have hanged himself.

Epstein served 13 months in jail about 10 years ago after reaching a deal with prosecutors that has since resurfaced and garnered widespread criticism for being too lenient. He was arrested in July and charged with trafficking dozens of underage girls from 2002 to 2005.