The FBI became close to correcting a mistake in the third and final warrant application renewal targeting onetime Trump campaign adviser Carter Page, but an FBI lawyer improperly altered a document to cover up that the bureau had erred in the previous filings.

In a report released on Monday, Justice Department Inspector General Michael Horowitz offered a detailed description of the actions taken by Kevin Clinesmith, a then-FBI lawyer who was part of special counsel Robert Mueller's team, that led to the criminal referral reported two weeks ago.

Horowitz, who looked into allegations of Foreign Intelligence Surveillance Act abuse, found the FBI made mistakes and omissions in the Russia investigation but did not determine that political bias tainted the effort.

Clinesmith is not named in Horowitz's report, but it is clear he is the "Office of General Counsel attorney" who had been acting in response to a question by an FBI agent that was part of the team investigating the Trump campaign.

"Supervisory Special Agent 2," who swore to an affidavit for all three FISA renewals against Page in 2017, told Horowitz's investigators that on the third renewal he wanted "a definitive answer to whether Page had ever been a source for another U.S. government agency before he signed the final renewal application."

While in contact with what was reportedly the CIA's liaison, Clinesmith was reminded that back in August 2016, predating the first Page warrant application in October 2016, the other agency informed the FBI that Page "did, in fact, have a prior relationship with that other agency."

An email from the other government agency's liaison was sent to Clinesmith, who then "altered the liaison's email by inserting the words 'not a source' into it, thus making it appear that the liaison had said that Page was 'not a source' for the other agency" and sent it to "Supervisory Special Agent 2," Horowitz found.

"Relying upon this altered email, [Clinesmith] signed the third renewal application that again failed to disclose Page's past relationship with the other agency," Horowitz wrote.

Consistent with the Inspector General Act of 1978, Horowitz said he informed Attorney General William Barr and FBI Director Christopher Wray with "relevant information" about Clinesmith's actions. The inspector general does not mention criminal referrals, but it has been reported that Clinesmith is now a subject of U.S. Attorney John Durham's criminal inquiry into the origins of the Russia investigation. The reports also said Clinesmith left the FBI after being confronted by Horowitz over his actions.

In a section on seven "significant inaccuracies and omissions" in the first Page FISA warrant application, Horowitz said the FBI left out that Page had been approved as an "operational contact" for the other agency from 2008 to 2013 and that Page "had provided information to the other agency concerning his prior contacts with certain Russian intelligence officers, one of which overlapped with facts asserted in the FISA application." Horowitz also found this other agency gave Page a "positive assessment," which was not included in the FISA warrant applications.

The agency is not identified in the report, but sources told the Washington Post it was the CIA and Page told the Daily Caller that he believes it was the same agency. The CIA declined the latter outlet's request for comment.

The initial FISA application and three renewals targeting Page required the approval of top members of the FBI, the Justice Department, and the Foreign Intelligence Surveillance Court, but they were also handled by lower-level officials. The initial warrant application was approved in October 2016, and renewals came at three-month intervals in January, April, and June 2017. Page was never charged with a crime as part of Mueller's investigation, which failed to establish a criminal conspiracy between the Trump campaign and the Kremlin, and he has denied being an agent for Russia.

Early media reports about Horowitz's report described Clinesmith as being a “low-level attorney,” but the inspector general previously described Clinesmith as “the primary FBI attorney assigned to [the Trump-Russia] investigation in early 2017.”

Clinesmith was an attorney with the FBI’s National Security and Cyber Law Branch. He worked under FBI General Counsel James Baker and Deputy General Counsel Trisha Anderson . He also worked on the Hillary Clinton email investigation and the Trump-Russia investigation. He was present in the FBI's meeting in Chicago with Trump campaign adviser George Papadopoulos in February 2017, Papadopoulos told lawmakers. An Australian diplomat's tip about Papadopoulos boasting to him that the Russians had damaging information about Hillary Clinton effectively prompted the FBI's counterintelligence investigation into the Trump campaign, dubbed "Crossfire Hurricane," in July 2016.

In a scathing July 2018 inspector general report on the FBI's Clinton emails investigation, Clinesmith was criticized at least 56 times as being one of the FBI officials who conveyed a bias against Trump in instant messages, along with Peter Strzok and FBI lawyer Lisa Page , both of whom have left the bureau.

In a lengthy instant message exchange between Clinesmith and another FBI employee on Nov. 9, 2016, the day after Trump’s presidential victory, he lamented Trump’s win and worried about the role he played in the investigation into Trump and his campaign. “My god damned name is all over the legal documents investigating his staff,” Clinesmith said, adding, “So, who knows if that breaks to him what he is going to do?”

Other messages showed Clinesmith, listed in Horowitz's report as "FBI Attorney 2," expressed favor toward Clinton and said, “Viva le resistance" in the weeks after Trump's win.

The July 2018 report shows Clinesmith claimed his messages reflected only his personal views and his work was unaffected by them, and Horowitz ultimately was unable to find "improper considerations, including political bias" improperly influenced any investigative decisions.