House intelligence committee chairman Rep. Devin Nunes has been the face of a memo expected to be released today that is fracturing relations between federal law enforcement and the president. But a little-known committee staffer whose last job was in the Justice Department put the explosive document together.

Kash Patel, according to sources familiar with the memo, read the highly classified intelligence it’s based on (something the Justice Department indicates Nunes has not done), drafted the memo, and then dealt with FBI and Justice Department efforts to keep it from being released to the public.

The FBI said on Wednesday that the memo has “material omissions of fact fundamentally impact the memo’s accuracy.”

Though Nunes said he recused himself from the committee’s Trump-Russia investigation after it was revealed he worked with the White House to derail the probe last spring, it was Patel never stepped back.

Patel has been “the drafter and the pusher of the memo,” one person familiar with the situation told The Daily Beast. On Capitol Hill, some even call it “the Kash memo.” The New York Times reported on Feb. 1 that the memo was “primarily written” by Patel.

Patel did not respond to a request for comment. Jack Langer, a spokesperson for Nunes, disputed this story.

“The problem is the lack of facts,” Langer said in an email. “Kash being the ‘driving force’ behind the memo is not a fact. Kash being the ‘pusher of the memo’ is not a fact. Unnamed people referring to ‘the Kash memo’ is not a fact.”

A source familiar with the investigation described Patel’s role simply as “a man on a mission.”

A year ago, Patel was a trial attorney in the Justice Department’s National Security Division. He worked on counterterror prosecutions, including that of an anti-government activist from Montana convicted for buying a sawed-off shotgun from an undercover FBI agent.

Patel won a small measure of infamy in February 2016 after a federal judge blasted him in an “order of ineptitude” after he showed up to court in casual clothes. “You don’t add a bit of value, do you?” the judge said to Patel, according to the Washington Post.

Nine months later, Donald Trump became president. In the weeks after Trump’s inauguration, while Patel was still working at the Justice Department, he reached out to the National Security Council about taking a position there, according to a person familiar with his outreach. Patel did not get a position because he had limited relevant experience, the person said. A second person familiar with Patel's outreach disputed that and said Patel had an impressive resume but didn't receive a position because there wasn't an opening when he reached out.

But he still made a move. Patel left the Justice Department for a position on the committee in April 2017, according to LegiStorm––a few weeks after Nunes made his infamous White House visit.

The Russia probe has been the dominant focus of Patel’s work on the committee, according to sources familiar with the committee’s investigation. Patel even traveled to London in search of Christopher Steele, a former British spy who authored the salacious Trump-Russia dossier, as The Daily Beast reported.

The memo reportedly discusses that dossier’s alleged role in Deputy Attorney General Rod Rosenstein’s application for an extension of a surveillance warrant on former Trump campaign advisor Carter Page. The memo is said to accuse Rosenstein of not telling a judge that Democrats helped fund the research project that the Steele dossier grew from. President Trump on Friday morning, hours before the memo is expected to be publicly released, ripped into the Department’s leadership on Twitter.

“The top Leadership and Investigators of the FBI and the Justice Department have politicized the sacred investigative process in favor of Democrats and against Republicans,” he tweeted.