NEWYou can now listen to Fox News articles!

EXCLUSIVE: Republican senators are demanding answers on why the Russian national who served as the sub-source for the debunked anti-Trump dossier was hired by the FBI as a confidential human source and paid with U.S. taxpayer dollars throughout the bureau’s original investigation into whether the Trump campaign colluded with Russia to influence the 2016 presidential election.

Sens. Chuck Grassley, R-Iowa, and Ron Johnson, R-Wis., in a letter exclusively obtained by Fox News Digital and sent to Attorney General Merrick Garland, are seeking all FBI and Justice Department records related to government payments to Igor Danchenko, along with the counterintelligence concerns he posed and the bureau’s decision to rely on him as a source.

Danchenko served as the primary source for the salacious anti-Trump dossier authored by ex-British intelligence officer Christopher Steele. The dossier was commissioned by opposition research firm Fusion GPS and paid for by the Hillary Clinton campaign and the Democratic National Committee through law firm Perkins Coie.

DURHAM PROBE: TRUMP TEAM SAYS AMERICANS SHOULD BE ‘WAITING FOR THE NEXT SHOE TO DROP’ AHEAD OF DANCHENKO TRIAL

Igor Danchenko, the primary sub-source for the Steele dossier, was indicted as part of Special Counsel John Durham’s investigations into the origins of the probe into whether the Trump campaign colluded with Russia to influence the 2016 presidential election. 

Igor Danchenko, the primary sub-source for the Steele dossier, was indicted as part of Special Counsel John Durham’s investigations into the origins of the probe into whether the Trump campaign colluded with Russia to influence the 2016 presidential election.  (AP Photo/Manuel Balce Ceneta))

But the questions from Grassley and Johnson come after Special Counsel John Durham, in a filing unsealed earlier this month, revealed that the FBI paid Danchenko to be a confidential human source for the FBI from January 2017 through October 2020.

Durham charged Danchenko last year with five counts of making false statements to the FBI. The charges stem from statements Danchenko made relating to the sources he used in providing information to an investigative firm in the United Kingdom.

The jury found that Special Counsel John Durham’s team had not proven beyond a reasonable doubt that Sussmann’s statement was a lie. 

The jury found that Special Counsel John Durham’s team had not proven beyond a reasonable doubt that Sussmann’s statement was a lie.  (REUTERS/Julia Nikhinson)

Despite the FBI paying Danchenko to serve as a confidential human source during the Trump administration—and during Special Counsel Robert Mueller’s investigation into whether members of the Trump campaign colluded with Russia to influence the 2016 presidential election—Danchenko was the subject of an FBI counterintelligence investigation from 2009 to 2011.

That FBI investigation into Danchenko focused on his contacts with suspected Russian intelligence officers and reported attempts to facilitate payments for classified information.

“The FBI, even in light of the extensive derogatory information attached to Danchenko, proceeded to pay him as a confidential human source three months later from March 2017 to October 2020 as part of Crossfire Hurricane,” Grassley and Johnson wrote to Garland. “Therefore, while we were investigating the Justice Department’s and FBI’s misconduct with respect to Crossfire Hurricane, you maintained him on the government’s payroll.”

DURHAM MOVES TO ADMIT EVIDENCE IN DANCHENKO TRIAL THAT MAY DISCREDIT TRUMP RITZ-CARLTON MOSCOW ALLEGATIONS

They added: “This extraordinary fact pattern requires additional information from the Justice Department and FBI relating to why Danchenko was placed on the payroll and paid by the taxpayer to assist in the federal government’s flawed investigation into President Trump.”

Grassley and Johnson demanded all records related to government payments made to Danchenko, the counterintelligence investigation into him, and his later hiring by the FBI by Oct. 22.

DOJ did not immediately respond to Fox News Digital’s request for comment on the letter.

Sen. Charles Grassley (R-IA) speaks to the media.

Sen. Charles Grassley (R-IA) speaks to the media. ((Photo by Kevin Dietsch/Getty Images))

Meanwhile, the Justice Department’s inspector general in 2019 revealed that the dossier helped serve as the basis for warrants obtained against former Trump campaign aide Carter Page.

FLASHBACK: SOURCE OF STEELE DOSSIER WAS INVESTIGATED BY FBI FOR RUSSIAN CONTACTS

The Justice Department admitted in 2020 that the FISA warrants to surveil Page, when stripped of the FBI’s misinformation, did not meet the necessary legal threshold and never should have been issued.

Sen. Ron Johnson (R-WI) arrives at a news conference.

Sen. Ron Johnson (R-WI) arrives at a news conference. (Photo by Anna Moneymaker/Getty Images)

Durham has indicted three people as part of his investigation: Danchenko in November 2021, Michael Sussmann in September 2021, and Kevin Clinesmith in August 2020.

Sussmann was found not guilty in June. Clinesmith pleaded guilty to altering an email about Carter Page to say that he was “not a source” for another government agency, even though Page has said he was a source for the CIA.

DESPITE ACQUITTAL, DURHAM TRIAL OF SUSSMANN ADDED TO EVIDENCE CLINTON CAMPAIGN PLOTTED TO TIE TRUMP TO RUSSIA

The Justice Department relied on Clinesmith’s assertion as it submitted its third and final renewal application in 2017 to eavesdrop on Page under the Foreign Intelligence Surveillance Act. Clinesmith pleaded guilty and in 2021 was sentenced to 12 months probation and 400 hours of community service.

Sources have told Fox News that Durham’s investigation is ongoing.