Rep. Devin Nunes, R-Calif., submitted a criminal referral notification to the Justice Department on Thursday, targeting individuals tied to the origins of the Trump-Russia investigation.

In a brief letter, Nunes informs Attorney General William Barr he and Rep. John Ratcliffe, R-Texas, want to meet to discuss eight criminal referrals, which are ready for consideration, as part of the House Intelligence Committee's years-long examination of alleged misconduct during the Russia probe.

“As part of that investigation, Committee Republicans identified several potential violations of the law,” Nunes, R-Calif., wrote in the letter to Barr on Thursday. Nunes said his staff will contact the DOJ to arrange a time.

Nunes, the ranking member of the House Intelligence Committee, has been teasing a referral of Justice Department and FBI officials for months. During a Fox News interview on Sunday, Nunes placed the referrals into three categories. The first, which Nunes described as "straight-up referrals," covered five individuals whose "crimes are lying to Congress, misleading Congress, leaking classified information." Two others related to "charges of conspiracy to lie to the Foreign Intelligence Surveillance Court" and the last to a "global leak referral."

Nunes' letter did not identify who was was subject to the referral, nor did it identify the alleged crimes.

The action on the referrals is now the hands of Barr, who is putting together a team to examine the FBI's initial investigation into President Trump's campaign in the summer of 2016. Asked about Nunes' criminal referrals during a congressional hearing this week, Barr testified, "Obviously, if there is a predicate for investigation, it will be conducted.”

During a Senate Appropriations hearing on Wednesday, Barr said, “Yes, I think spying did occur” and “I think spying on a political campaign is a big deal.” When offered a chance to withdraw the remark, he instead clarified: “I want to make sure there was no unauthorized surveillance.”

Hours after the notification was sent to Barr, Nunes said the public may never know who is mentioned in criminal referrals. "We don't know if you'll ever know who" is named, Nunes told Fox News host Sean Hannity. "But I can tell you that if you follow the Russia hoax closely, if I gave you seven guesses, you'd probably get the five people that we have referred."

Nunes and other top GOP investigators have placed great faith in Barr to make headway toward completing an investigation begun last year by a joint GOP-led task force comprising the Judiciary Committee and the Oversight Committee. Key to this effort, which has been bolstered by intelligence panel Republicans, was investigators looking over roughly 15 transcripts of interviews conducted by the task force last year.

In recent weeks, House Judiciary Committee ranking member Doug Collins, R-Ga., released transcripts of the private interviews of former FBI agent Peter Strzok, former FBI lawyer Lisa Page, Justice Department official Bruce Ohr, his wife and former Fusion GPS contractor Nellie Ohr, former Trump campaign aide George Papadopoulos, former top FBI official Bill Priestap, and former FBI general counsel James Baker.

A potential contributing factor to Nunes' efforts is the House Intelligence Committee's vote last fall to release the transcripts of more than 50 interviews it conducted in its now-completed Russia investigation, which had been submitted to the Office of the Director of National Intelligence for declassification review.

President Trump urged then-Attorney General Jeff Sessions back in August 2018 to investigate any possible abuses by the DOJ and FBI, tweeting out: “Look into all of the corruption on the ‘other side’ including deleted Emails, Comey lies & leaks, Mueller conflicts, McCabe, Strzok, Page, Ohr, FISA abuse, Christopher Steele & his phony and corrupt Dossier, the Clinton Foundation, illegal surveillance of Trump Campaign, Russian collusion by Dems — and so much more.”

Nunes has railed against what he says is collusion between the Democrats and the Russians, pointing to use of the unverified Trump dossier by the FBI to obtain FISA warrants to spy on onetime Trump campaign official Carter Page as proof of an unraveling operation to undermine the president. That dossier, compiled by British ex-spy Christopher Steele during his time working for Fusion GPS, was funded in part by Hillary Clinton's campaign and the Democratic National Committee through the Perkins Coie law firm. The dossier was also given to multiple members of the media.

As noted in the GOP majority memo from the House Intelligence Committee last year, details like the dossier's Democratic benefactors and its author's anti-Trump bias were left out of the FISA warrant applications, which has alarmed Republican investigators concerned about political bias.

The criminal referrals came together as special counsel Robert Mueller concluded his investigation into Russian interference in the 2016 election and possible collusion between the Trump campaign and Russia. Although Barr said in a summary of Mueller's team could not establish criminal conspiracy between the Trump team and Russia, some Democrats, including House Intelligence Committee Chairman Adam Schiff, D-Calif., insist there is clear evidence of collusion.

According to Barr, DOJ Inspector General Michael Horowitz's investigation into possible abuse of the Foreign Intelligence Surveillance Act by the DOJ and FBI should be finished by May or June. That investigation was launched in March 2018.

The DOJ IG’s office said it would “examine the Justice Department’s and the FBI’s compliance with legal requirements, and with applicable DOJ and FBI policies and procedures, in applications filed with the U.S. Foreign Intelligence Surveillance Court relating to a certain U.S. person.” That “certain U.S. person” is Carter Page.

The IG also promised to “review information that was known to the DOJ and the FBI at the time the applications were filed from or about an alleged FBI confidential source. Additionally, the OIG will review the DOJ’s and FBI’s relationship and communications with the alleged source as they relate to the FISC applications.” The “alleged FBI confidential source” is Christopher Steele.

Trump questioned the efficacy of the DOJ IG's investigation in February 2018, tweeting: "Why is A.G. Jeff Sessions asking the Inspector General to investigate potentially massive FISA abuse? Will take forever, has no prosecutorial power, and already late with reports on Comey etc. Isn’t the I.G. an Obama guy? Why not use Justice Department lawyers? DISGRACEFUL!"

In addition to the DOJ IG’s probe, U.S. Attorney John Huber is also conducting an investigation. A March 2018 letter from Republicans in Congress asked then-Attorney General Jeff Sessions to appoint a second special counsel to look into “certain decisions made and not made by the Department of Justice and FBI in 2016 and 2017” which they believed showed “evidence of bias, trending toward animus, among those charged with investigating serious cases.” Instead of a special counsel, Sessions tasked Huber with this mission later in March 2018. The status of his parallel probe is not known.

Democrats have long argued that the FBI acted appropriately in obtaining the authority to spy on the Trump campaign due to concerns about Russian influence. In a rebuttal to the House Intelligence GOP memo which alleged the FBI did not reveal the dossier's Democratic benefactors or Steele's anti-Trump bias in obtaining FISA warrants to spy on Page, Democrats argued the DOJ and FBI "met the rigor, transparency, and evidentiary basis needed to meet FISA's probable cause requirement."

Both Nunes and GOP ally Rep. Mark Meadows of North Carolina have suggested their investigative effort could expand to encompass dozens of people, including more criminal referrals in the future.

"We think there's only a few people behind these leaks, but there could be multiple people, so on the global leak referral, there could be several individuals," Nunes said Sunday. "When you look at the conspiracy that could get up to a dozen, two dozen people."