U.S. Attorney John Durham is reportedly reviewing John Brennan’s analysis of Russian election interference, including scrutiny of the former Obama CIA director’s handling of a secret source said to be close to the Kremlin.

Durham, who was selected by Attorney General William Barr in 2019 to look into the origins of the Trump-Russia investigation and the government’s response to Moscow’s meddling, is investigating whether Brennan’s CIA was attempting to keep other agencies in the dark as he pushed for a specific, preconceived analytic assessment about Russia’s true intentions in 2016, the New York Times reported Thursday.

The top Connecticut prosecutor’s team reviewed emails from the CIA, FBI, and National Security Agency analysts who came together to assess Russia’s interference, the new report revealed, and Durham’s investigators pressed for answers about why some agencies at least temporarily denied other agencies access to secretive intelligence about the Kremlin’s active-measures campaign.

Durham interviewed agents and analysts from all three agencies, and the report said he was scrutinizing whether the clash over intelligence-sharing was the typical sort of bureaucratic turf battle over jealously guarded secrets or an effort to cover something up.

Much of this revolves around how the United States government eventually reached its January 2017 intelligence assessment on Russian meddling and whether Brennan was pushing for a biased result.

One major battle was about the identity and credibility of a CIA source allegedly close to the Kremlin. The NSA wanted more details about him, which the CIA resisted before providing them. The NSA then disagreed with the CIA and FBI about how much confidence to place in the source.

At least some intelligence officials were disturbed by a law enforcement officer such as Durham inquiring into the assessments made by intelligence agencies, though Durham played a similar role in his Obama-era investigation into the CIA's destruction of tapes showing the harsh interrogation of detainees.

Durham hasn’t yet interviewed Brennan, though the report said his emails and other records have been requested from the CIA by the U.S. attorney. Retired Adm. Mike Rogers, who was head of the NSA at the time, was interviewed by Durham last summer and fall.

The January 2017 intelligence community assessment in question concluded with "high confidence" that Russian President Vladimir Putin “ordered an influence campaign in 2016” and that Russia worked to “undermine public faith in the U.S. democratic process, denigrate former Secretary of State [Hillary] Clinton, and harm her electability and potential presidency” and “developed a clear preference for President-elect Trump.” The NSA diverged on one aspect, expressing only “moderate confidence” that Putin actively tried to help Trump’s election chances and harm those of Clinton by contrasting her unfavorably.

“I wouldn’t call it a discrepancy, I’d call it an honest difference of opinion between three different organizations, and, in the end, I made that call,” Rogers told the Senate in May 2017. “It didn’t have the same level of sourcing and the same level of multiple sources.”

It was Brennan’s still-classified “wake-up call” intelligence that prompted the Obama administration to reconsider how it viewed Russia's hacking of the Democratic National Committee, the Senate Intelligence Committee revealed last week. The specifics of the intelligence that jolted Barack Obama's national security team into action is detailed in a blacked-out section, titled “[Redacted] Intelligence Was The ‘Wake Up’ Call.”

Within an hour or two of being briefed on the intelligence, then-national security adviser Susan Rice said Obama needed to know.

Rice said “the president's reaction was of grave concern,” which “prompted her to call the first of a series of restricted small-group Principals Committee meetings on the topic.”

“During the meeting with the President, Director Brennan also advised the President of a plan to brief key individuals, including congressional leadership, but not to disseminate the intelligence via routine reporting channels,” the Senate report stated.

The committee noted “the receipt of the sensitive intelligence prompted the National Security Council to begin a series of restricted Principals Committee meetings to craft the administration's response” and said the discussions “were atypically restricted” and “excluded” key officials who were normally clued in.

Former Director of National Intelligence James Clapper and U.S. Ambassador to the United Nations Samantha Power said that “the extraordinarily restricted nature of the meetings and departure from routine methods of disseminating intelligence were reminiscent” of how they handled preparations for the Osama bin Laden raid. Former Deputy Attorney General Sally Yates called it “very cloak-and-dagger.”

The list even initially excluded the secretary of state, the defense secretary, the chairman of the Joint Chiefs, and the Treasury secretary.

“Several NSC officials who would normally be included in discussions of importance, such as the NSC Senior Director for Russia, the Senior Director for Intelligence Programs, and the White House Cybersecurity Coordinator, were neither included in the discussions nor exposed to the sensitive intelligence until after the election,” the report said.

The Brennan-relayed intelligence was likely detailed in a June 2017 Washington Post article, which stated that in early August 2016, the CIA sent an “eyes only” envelope addressed to Obama that contained an “intelligence bombshell … from sourcing deep inside the Russian government” that detailed Putin’s “specific instructions” to help Trump and hurt Clinton in 2016. The material was said to be so sensitive it was kept out of the President’s Daily Brief.

One day after Trump gave Barr “full and complete” declassification authority to examine the origins of the Trump-Russia investigation in May 2019, the New York Times published a piece on this source “long-nurtured by the CIA” whom the outlet hinted was now in danger of being exposed in Russia — but he had already left the country. The source’s initial resistance to being pulled out reportedly led some to question whether he might be a double agent.

Hotly disputed reporting by CNN and others in September 2019 about the reasons for the alleged source’s apparent 2017 exfiltration from Russia eventually exposed his identity and revealed he was living in the D.C. area. He’s since been moved, and it is not known whether Durham has questioned him.