Attorney General William Barr has reportedly tapped “hard-charging, bulldog” U.S. Attorney John Durham to investigate the investigators, seeking to determine if FBI intelligence collection efforts targeting then-candidate Donald Trump’s campaign were “lawful and appropriate.”

And while this was first reported Monday evening, Fox News is now reporting that Durham has been on the case “for weeks.”

Per our Jake Gibson: Sources tell @FoxNews that CT US Attorney John Durham has been working on the investigation into the origins of the FBI’s counterintelligence investigation into Russian meddling in the 2016 presidential election and the Trump Campaign for “weeks.” — John Roberts (@johnrobertsFox) May 14, 2019

The issuance of Foreign Intelligence Surveillance Act (FISA) warrants will be central to Durham’s investigation.

Durham will also be investigating whether Democrats were the ones who improperly colluded with foreign actors — this after recent reports that Ukrainian players may have leaked damaging information about then-campaign chairman Paul Manafort to help Hillary Clinton’s campaign.

More from Fox News on the details of the new probe:

Durham, known as a “hard-charging, bulldog” prosecutor, according to a source, will focus on the period before Nov. 7, 2016—including the use and assignments of FBI informants, as well as alleged improper issuance of Foreign Intelligence Surveillance Act (FISA) warrants. Durham was asked to help Barr to “ensure that intelligence collection activities by the U.S. Government related to the Trump 2016 Presidential Campaign were lawful and appropriate.” A source also told Fox News that Barr is working “collaboratively” on the investigation with CIA Director Gina Haspel and Director of National Intelligence Dan Coats, and that Durham is also working directly with Justice Department Inspector General Michael Horowitz, who is currently reviewing allegations of misconduct in issuance of FISA warrants, and the role of FBI informants during the early stages of the investigation.

President Trump, who has called the Russian collusion probe and the surveillance of his campaign a scandal “bigger than Watergate,” shut down critics who have claimed he ordered Barr to appoint Durham, telling reporters Tuesday at the White House he did not do so.

“It’s the greatest hoax ever perpetrated on the people of this country,” he said from the White House lawn.

The president also praised Barr for the act.

“I think it’s a great thing that he did it,” Trump said. “I am so proud of our attorney general that he’s looking into it.”

Trump is "so proud" of Barr for investigating how Russia probe began pic.twitter.com/4sz42oHeXS — TPM Livewire (@TPMLiveWire) May 14, 2019

Barr said on April 9, while testifying before Congress, that he would be launching a probe of whether there was any improper or unauthorized surveillance of members of the Trump campaign.

“I am reviewing the conduct of the investigation and trying to get my arms around the aspects of the counterintelligence investigation that was conducted in the summer of 2016,” Barr testified.

This being independent from an ongoing investigation from the Justice Department inspector general.

A quick sampling of social media users shows that even at four weeks, it’s well past time the investigation has gotten underway.

Here’s a sampling of responses from Twitter:

Weeks? Durham has been on the case at least *seven months*. James Baker's lawyer told @Jim_Jordan Durham was on the case on October 3, 2018. https://t.co/PdkEDhMEWW — Phil Kerpen (@kerpen) May 14, 2019

Context: Jordan was asking about leaks to reporters, different than but potentially related to question of origin Durham is now investigating. — Phil Kerpen (@kerpen) May 14, 2019

No leaks about it either. Expect an all out attack by media n Dems. Those who attack the loudest are cornered. OIG report is to show many media were complicit in getting Fisa warrants. @realDonaldTrump @ScottAdamsSays @VicToensing @kanyewest @hrtablaze @usminority @hodgetwins https://t.co/extMrlPcPJ — Frank M. (@Teamnguns) May 14, 2019

Great news. Hopefully he’ll beat the statute of limitations. — Harriet Baldwin ?? (@HarrietBaldwin) May 14, 2019

Good!!!! It’s time???????? — Lauren Nelson (@LaurenN36341359) May 14, 2019

I hope it’s been longer than weeks. It’s well overdue. — MsD (@MsD_408) May 14, 2019

This should be a real barn burner — Help For Dogs (@FixSheltersNow) May 14, 2019

I believe the Baker transcript of his testimony reveals Durham’s involvement since at least then. Barr appointing him may simply be the formality of naming him as the lead prosecutor going forward with indictments. — Deplorable Trumpfan ⭐️⭐️⭐️ (@JCMac65) May 14, 2019