The former director of the National Security Agency is the latest to sit down with U.S. Attorney John Durham in the widening inquiry into the origins and conduct of the Trump-Russia investigation.

Adm. Mike Rogers, who retired in 2018 after four years as NSA chief and commander of U.S. Cyber Command, has met with Durham, who is working at the behest of Attorney General William Barr, multiple times and is cooperating voluntarily in Durham's deep dive into the FBI’s counterintelligence investigation related to the Trump campaign and the Russian government, according to the Intercept. Rogers is likely being talked to because of his key intelligence perch, experiences uncovering Foreign Intelligence Surveillance Act violations, and his role in the intelligence community's assessment of Russian interference.

The December report by Justice Department Inspector General Michael Horowitz on FISA abuses by the DOJ and the FBI criticized the bureau’s reliance on British ex-spy Christopher Steele’s unverified dossier in pursuing electronic surveillance against Trump campaign associate Carter Page.

In 2016, Rogers helped expose FISA flaws of a different kind by the NSA and the FBI. That October, as the bureau received its first Page surveillance warrant, Rogers notified the FISA Court of an NSA inspector general report that found the agency was pulling data directly from the internet and improperly searching it for information related to Americans in violation of FISA laws dealing with foreigners outside the United States targeted by U.S. intelligence agencies.

A FISA Court ruling from April 2017 revealed the high volume of violations, and that month the NSA announced it ended all searches where the foreign intelligence target was neither the sender nor receiver of a communication but was mentioned within it.

"That in doing this we were going to lose some intelligence value, but my concern was I just felt it was important — we needed to be able to show that we are fully compliant with the law," Rogers told the Senate in 2017.

The same FISA Court ruling stated that, by early 2016, the DOJ learned the FBI gave contractors access to massive amounts of FISA information well beyond what was necessary to respond to FBI requests. Another recently declassified October 2018 FISA Court ruling stemming from the court's inquiry into these FISA abuses found the bureau violated constitutional protections against unreasonable searches and seizures.

Horowitz's report also detailed how Rogers and the NSA viewed Steele's dossier with skepticism, pushing back against efforts by then-FBI Director James Comey and then-FBI Deputy Director Andrew McCabe to include information from it in the high-profile January 2017 assessment on Russian election interference put together by the CIA, the FBI, and the NSA.

Rogers and Comey, along with Director of National Intelligence James Clapper and CIA Director John Brennan, who is being scrutinized by Durham, briefed President-elect Trump about their findings at Trump Tower. Comey stayed to tell Trump about some of the dossier's more salacious allegations.

The assessment 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 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, and Durham is likely looking into whether Steele's dossier played a role in the determinations of the other agencies.

“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.”

Rogers was a Russia hawk, however, telling the Senate in February 2018 about Russia’s plans of “stirring discord in the West” and how “this threatens the foundations of democracy.”

“More broadly, my concern is that President Putin has clearly come to the conclusion that there’s little price to pay here," Rogers said. "Clearly, what we have done is not enough.”

“I was glad to see the broad direction that we were moving in," Rogers said in a post-retirement interview last year. "But I'm not going to pretend for a minute it's perfect by any stretch of the imagination.”