Aspects of U.S. Attorney John Huber’s investigation into the Clinton Foundation have been assumed by U.S. Attorney John Durham as part of his review into the origins of the Russia probe, Fox News has learned.

A source familiar with Durham’s investigation told Fox News on Thursday that parts of what Huber was investigating in 2017 -- involving the Clinton Foundation -- have been incorporated in Durham’s investigation.

FLASHBACK: SESSIONS DIRECTS JOHN HUBER TO 'EVALUATE CERTAIN ISSUES' INVOLVING URANIUM ONE, CLINTON FOUNDATION

In November 2017, then-Attorney General Jeff Sessions directed Huber, the U.S. attorney for Utah, and other senior prosecutors to evaluate “certain issues” involving the sale of Uranium One, and other dealings related to the Clinton Foundation. Sessions tapped Huber after requests by congressional Republicans, who had been calling for the appointment of a special counsel to review the matters.

Sessions revealed that he asked U.S. Attorney John Huber, seen here, to look into the accusations.

Huber was also tasked with reviewing the FBI’s handling of the Clinton email probe, including allegations that the Justice Department and FBI “policies or procedures” were not followed.

It has been unclear, for years, the status of Huber's investigation, but another source told Fox News Thursday that Huber has faced mounting criticism from the Justice Department and White House over his progress.

"There are folks that are aware of the fact that Huber has not done much, and there has been criticism at the Justice Department and the White House," the source said. "Folks that have been concerned about what he did or didn't do, and many of them feel that Huber did not dig deep enough or work hard enough."

The source added that many are "very concerned about why there hadn't been more done."

The New York Times on Thursday first reported that Durham has focused attention on the Clintons, and said that Durham has sought documents and interviews about how federal law enforcement officials handled an investigation into allegations of political corruption at the Clinton Foundation.

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Durham was appointed by Attorney General Barr last year to investigate the origins of the FBI’s Russia probe shortly after Mueller completed his yearslong investigation into whether the campaign colluded with the Russians to influence the 2016 presidential election.

Durham’s timeline has been focused on July 2016, when the FBI’s original Russia probe began, through the appointment of Mueller in May 2017.

Durham’s investigation has been slowed by the coronavirus pandemic, but that has not blunted the level of anticipation from President Trump, his Republican allies on Capitol Hill and his supporters, some of whom have called for findings to be released before November's presidential election.

Speculation over the status of Durham's review into the origins of the Russia probe has only intensified amid the resignation of a top aide earlier this month, Norah Dannehy, and comments from congressional Republicans suggesting developments could soon be announced.

Dannehy, a top aide to Durham, resigned Friday, after working closely with the U.S. attorney for Connecticut for years. Durham’s office confirmed her departure but did not elaborate on the backstory.

DURHAM SPECULATION REACHING FEVER PITCH 

Earlier this month, Senate Judiciary Committee Chairman Lindsey Graham, R-S.C., hinted that developments in Durham’s investigation were on the horizon. This was after newly released Justice Department records showed numerous phones belonging to members of former Special Counsel Robert Mueller’s team were wiped of information because of forgotten passcodes, irreparable screen damage, loss of the device, intentional deletion or other reasons—all before the Justice Department inspector general’s office could review the devices.

“You think you are mad about the phones being wiped?” Graham said on Fox News' “Hannity” last week. “Stay tuned.”

He added: “We’ll talk in about 10 or 12 days and we’ll see if there is something else you can get mad about.”

The investigation has produced one criminal charge so far, against former FBI lawyer Kevin Clinesmith, who was accused of altering an email related to the surveillance of a former Trump campaign aide. But that prosecution did not allege a broader conspiracy within the FBI, and the conduct it involved had largely been laid out in a Justice Department inspector general report from last December.

It is not clear if Durham will be able to conclude his work before the election, though Barr has not ruled out the possibility of additional criminal charges.

Barr, during an interview with NBC News last week, said that there “could be” more charges stemming from Durham's review.

“Yeah, there could be,” Barr said while declining to say whether any such charges would be announced prior to Election Day.

In July, though, Fox News reported that Durham could wait to reveal his findings or initiate further prosecutions until after the 2020 presidential election.

Two sources familiar with Durham’s investigation told Fox News at the time that Durham was working expeditiously to try to finish the probe before Labor Day — which he did not — but that several lines of the investigation had not yet been completed.

“He believes it’s critical to do them,” one source said at the time. “He is feeling more pressure to get this done and wrapped up.”

The source also told Fox News that Durham “does not want this to be viewed political,” and the closer it gets to November, Durham could “punt it to after the election.”