Attorney General William Barr has appointed US Attorney John H. Durham of Connecticut to examine the origins of the Trump-Russia investigation to determine if the FBI's spying on the Trump campaign was "lawful and appropriate," according to Fox News.

U.S. Attorney John Durham has been assigned to probe the origins of the surveillance of the Trump campaign, a source told Fox News. (Justice Department)

The move comes as the Trump administration has demanded answers over the use of "informants" on his 2016 campaign.

According to Fox, Barr is "serious" and has assembled a team from the DOJ to participate in the probe, adding that Durham is known as a "hard-charging, bulldog" prosecutor according to their source.

Sources familiar with matter say the focus of the probe includes the pre-transition period -- prior to Nov. 7, 2016 - - including the use and initiation of informants, as well as potential Foreign Intelligence Surveillance Act (FISA) abuses. An informant working for U.S. intelligence posed as a Cambridge University research assistant in September 2016 to try extracting any possible ties between the Trump campaign and Russia from George Papadopoulos, then a Trump foreign policy adviser, it emerged earlier this month. Papadopoulos told Fox News the informant tried to "seduce" him as part of the "bizarre" episode. Durham previously has investigated law enforcement corruption, the destruction of CIA videotapes and the Boston FBI office's relationship with mobsters. He is set to continue to serve as the chief federal prosecutor in Connecticut. -Fox News

Of note - in January House Republicans Jim Jordan and Mark Meadows wrote to Durham, saying that they had "discovered" he was "investigating former FBI General Counsel James Baker" over unauthorized leaks to the media, adding "We know the DOJ and FBI departed from traditional investigative and prosecutorial practices, and insufficiently adhered to the Foreign Intelligence Surveillance Act (FISA).

Durham has a history of serving as a special prosecutor, investigating wrongdoing among national security officials - including the FBI's ties to a Boston crime boss, as well as accusations of CIA detainee abuse.

According to the report, Durham's review would run in parallel with the ongoing DOJ probe by Inspector General (IG) Michael Horowitz. Meanwhile, Republicans have been seeking answers from US Attorney for Utah, John Huber, who was appointed by former AG Jeff Sessions to review FBI and DOJ surveillance abuses, as well as authorities' handling of the probe into the Clinton Foundation.

Not much has come of Huber's investigation, while Republicans have cautioned that he has spoken with few key witnesses and whistleblowers.

Durham's appointment comes about a month after Barr told members of Congress he believed "spying did occur" on the Trump campaign in 2016. He later said he didn't mean anything pejorative and was gathering a team to look into the origins of the special counsel's investigation. Democrats have pummeled Barr in frustration following revelations in Special Counsel Robert Mueller's report that the Trump campaign did not collude with Russian actors, despite numerous offers by Russians to assist the campaign. Mueller's final report has led to a bitter D.C. battle over the limited number of redactions in the report, which the DOJ says are legally necessary because they pertain to grand jury matters. -Fox News

As part of the FBI's FISA application on Trump campaign aide Carter Page, the FBI cut-and-pasted from a disputed Washington Post article which suggested that the Trump campaign may have been compromised. The agency also repeatedly told the FISA court that it "did not believe" UK ex-spy Christopher Steele was the source of a Yahoo News article written by Michael Isikoff which implicated Page in Russian collusion.

London court records, however, reveal that contrary to the FBI's statements, Steele had briefed Yahoo News and other media outlets in the fall of 2016 at the urging of his employer Fusion GPS - which the Clinton campaign and the Democratic National Committee (DNC) had paid for anti-Trump opposition research. This information was withheld from FISA judges during the application to surveil Page.

What's more, the FBI could not verify the dodgy dossier Steele assembled. Speaking Fox on 'Sunday Morning Futures,' Senate Judiciary Committee Chairman Lindsey Graham said "There's a document that's classified that I'm gonna try to get unclassified that takes the dossier -- all the pages of it -- and it has verification to one side," adding "There really is no verification, other than media reports that were generated by reporters that received the dossier."

Graham cited a recent report from The Hill's John Solomon which reveals that the FBI was specifically informed that Steele had admitted he was "keen" to influence the 2016 election with his document.

Deputy Assistant Secretary of State Kathleen Kavalec’s written account of her Oct. 11, 2016, meeting with FBI informant Christopher Steele shows the Hillary Clinton campaign-funded British intelligence operative admitted that his research was political and facing an Election Day deadline. -The Hill

Solomon also reported last week that a high-ranking government official who met with Christopher Steele in October 2016 determined that information in the Trump-Russia dossier was inaccurate, and likely leaked to the media.

Ten days before the FBI used the now-discredited dossier to apply for a Foreign Intelligence Surveillance Act (FISA) warrant to spy on Trump campaign aide Carter Page, Steele met with Deputy Assistant Secretary of State Kathleen Kavalec, who took handwritten notes of the encounter.

Steele told Kavalec that Russia had a "technical/human operation run out of Moscow targeting the election," which recruited US emigres to "do hacking and recruiting. Steele added that "Payments to those recruited are made out of the Russian consulate in Miami."

Except that's a lie - as Kavalec debunked the assertion in a bracketed comment: "It is important to note that there is no Russian consulate in Miami."

What makes this particularly damning is that the FBI swore on October 21, 2016 to the FISA judges that Steele's "reporting has been corroborated and used in criminal proceedings,"and that the FBI deemed him to be "reliable" and was "unaware of any derogatory information pertaining" to the former British spy who was working for Fusion GPS - the firm paid by the DNC and the Clinton campaign to come up with dirt on Donald Trump.

And now U.S. Attorney John Durham will sort out exactly what happened, we can only hope.