Rep. Devin Nunes said U.S. Attorney John Durham needs to convene a grand jury in his review of the origins of the Russia investigation to determine the full extent of the role played by the Steele dossier in the FBI's work.

"The U.S. attorney in Connecticut needs to get all this information quickly as possible and then interview all these people under oath in front of a grand jury," the California Republican said Wednesday evening on Fox News.

Durham was tasked by Attorney General William Barr earlier this year to examine the early stages of the counterintelligence investigation into the Trump campaign, which the FBI says began in July 2016. He has the ability to convene a grand jury and subpoena people outside of the government.

Nunes, who is the ranking member of the House Intelligence Committee, told host Sean Hannity that Justice Department Inspector General Michael Horowitz also needs to clear up some inconsistencies in his investigation into alleged abuse of the Foreign Intelligence Surveillance Act. Barr has said he is working closely with Horowitz in his investigative effort.

Nunes said the source for reports Tuesday about Horowitz's team interviewing Steele, which indicated Steele was credible and thus extended the investigation, was probably the British ex-spy himself. Steele is the author of the unsubstantiated and salacious dossier on President Trump that was used by the FBI to obtain FISA warrants to surveil onetime Trump campaign aide Carter Page.

"We also know the FBI has told Congress that they didn't know anything about the Steele dossier until September 2016, another lie because we know from the interviews with [Justice Department official] Bruce Ohr and others and even Andrew Weissmann, the 'pitbull' for [special counsel Robert] Mueller, that he was actually briefed on the dossiers in 2016," Nunes said.

A Fox News report last week said at least one key witness who is not part of the DOJ or the FBI came forward only after Barr tasked Durham to lead the review of the origins of the Russia investigation. It now appears Steele was the subject of this "breakthrough."

Four FISA warrant applications and renewals were filed from October 2016 through June 2017 against Page. The applications relied heavily on the unverified dossier compiled by Steele, who was hired by Fusion GPS. The opposition research firm was hired by Marc Elias of the Perkins Coie law firm at the behest of the Clinton presidential campaign. Steele and Fusion GPS shopped the research around to various government figures, including one skeptical State Department official, as well as the media in the run-up to the 2016 election.

In a Fox News interview Tuesday evening, Nunes said if Steele wants to clear his name, he needs to testify before Congress.

Nunes said in an interview late last month that he wants to ask Mueller how far the counterintelligence investigation into Trump's campaign goes when the former special counsel of the Russia investigation testifies on July 17. Democrats have dismissed the GOP's excitement about Horowitz's inquiry and Steele's role in it as "whataboutism" run amok.