WASHINGTON (NewsNation) — A former FBI lawyer plans to plead guilty to making a false statement in the first criminal case arising from U.S. Attorney John Durham’s investigation into the origins of how the FBI and other intelligence agencies pursued the probe of Russia’s election interference in 2016.

Kevin Clinesmith is expected to plead guilty to one count of making a false statement related to the altering of a government email about a former Trump campaign adviser who was a target of FBI surveillance, attorney Justin Shur told The Associated Press.

The Durham investigation is examining whether the intelligence-gathering, assessment and surveillance methods used in the Russian probe was legal and appropriate by the FBI and other agencies.

Durham, the U.S. attorney for Connecticut, had no comment, a spokesman said. It remains unclear what additional charges, if any, Durham might bring.

Clinesmith was referred for potential prosecution by the department’s inspector general’s office, which conducted its own review of the Russia investigation. Clinesmith resigned from the FBI last year.

That review concluded that the FBI made significant errors and omissions as it applied for secret national security warrants to eavesdrop on former Trump campaign adviser Carter Page.

Specifically, the inspector general accused Clinesmith, though not by name, of altering an email about Page to say that he was “not a source” for another government agency and forwarding it along. Page has said he was a source for the CIA.

The Justice Department relied on that assertion as it submitted a third and final renewal application in 2017 to eavesdrop on Page under the Foreign Intelligence Surveillance Act (FISA).

Clinesmith told the inspector general that from his conversations he did not understand Page to be a source, or a “recruited asset,” or to have a direct relationship with another government agency. But that relationship was seen as something important to disclose to the FISA court, especially if Page was being tasked by the government to have interactions with Russians.

“Kevin deeply regrets having altered the email,” Shur said. “It was never his intent to mislead the court or his colleagues, as he believed the information he relayed was accurate, but Kevin understands what he did was wrong and accepts responsibility.”

President Donald Trump addressed the developments Friday at the beginning of a White House briefing.

“Kevin Clinesmith, a corrupt FBI attorney who falsified FISA warrants in James Comey’s very corrupt FBI is expected to plead guilty. You probably just heard that; it just came out. So that’s just the beginning, I would imagine, because what happened should never happen again. So he is pleading guilty. Terrible thing, terrible thing. The fact is, they spied on my campaign, and they got caught. And you’ll be hearing more.”

The Associated Press contributed to this report.