FBI deputy director Dan Bongino will step down from his post next month, ending a short but tumultuous tenure as the bureau's second-highest-ranking official.
Mr Bongino announced the move on social media on Wednesday, hours after US President Donald Trump said he thought the former right-wing podcaster wanted to "go back to his show".
"Dan did a great job," Mr Trump told reporters.
The 51-year-old was considered an unusual pick for the post, which historically had been filled by career agents who had worked their way up the ranks.
Mr Bongino's resume highlights included work as a New York City police officer, a member of the Secret Service and host of The Dan Bongino Show.
His appointment was objected by the FBI Agents Association, a group representing 14,000 primarily current agents after FBI Director Kash Patel vowed to install a career agent.
"I want to thank President Trump, AG Bondi, and Director Patel for the opportunity to serve with purpose," Mr Bongino wrote in a post on X, referring to Attorney General Pam Bondi and FBI Director Kash Patel.
Mr Bongino's office has already been boxed up, according to several people familiar with the matter, who spoke with Reuters.
However, another person said he was working at FBI Headquarters on Wednesday.
Bongino's chequered work history
As a podcaster, Mr Bongino promoted a range of conspiracy theories that came back to haunt him once he was handed a position of power.
He circulated false information relating to the January 6, 2021 assault on the US Capitol by supporters of Mr Trump, including that the planting of pipe bombs at the Democratic and Republican national committee offices the night before was an "inside job" by the FBI.
That assertion was walked back in December when the FBI arrested a suspect in the five-year-old case.
In a Fox News interview afterward, Mr Bongino appeared to say he had been paid to voice controversial opinions.
"I was paid in the past, Sean, for my opinions, that's clear, and one day I will be back in that space — but that's not what I'm paid for now," he told television presenter, Sean Hannity.
"I'm paid to be your deputy director, and we base investigations on facts."
Mr Bongino's tenure at the FBI has been in question since July, when issues related to the release of the Epstein files came to a head.
That month, the Department of Justice and FBI leadership jointly issued a memo that backtracked on the Trump administration's pledge for transparency, pouring cold water on a variety of long-held conspiracy theories that Mr Bongino had previously promoted on his podcast.
The memo enraged many of Trump's followers, who rejected assertions that there was no incriminating "client list" to release and that Epstein died by suicide in his jail cell.
Reuters