Retired Army Gen. David Petraeus is providing rare, Saturday testimony on Capitol Hill, talking privately with the Republican-led House committee investigating the fatal 2012 terror attacks in Benghazi, Libya.

Petraeus was the CIA director at the time of the attacks and is testifying for the second time before the chamber’s Select Committee on Benghazi .

He is expected to testify Saturday for three or four hours to “tie up loose ends” from his visit in early January, Fox News is told.

The Sept. 11, 2012, terror attacks on a U.S. outpost in Benghazi killed U.S. Ambassador J. Christopher Stevens, Foreign Service Officer Sean Smith and two CIA contractors.

The selected committee was formed in 2014 to investigate the attacks including whether the Obama administration failed to provide adequate security for the outpost, who committed the strikes and if officials tried to mislead the public by suggesting an online, anti-Muslim video sparked the attacks.

Then-Secretary of State Hillary Clinton, who is now the 2016 Democratic presidential frontrunner, testified in October 2015 before the committee, which has so far interviewed at least 75 witnesses. She also tesified before Congress on the matter in 2013.  

Democrats and others argue the committee’s interviews, subpoena requests and other, related activities are largely wasting millions in taxpayer dollars and is essentially election-season theater to hurt Clinton’s campaign.

One of the major sticking points in the Benghazi inquiry focuses on the public talking points that the CIA drafted, particularly the role then-Deputy CIA Director Mike Morell played in writing them.

Petraeus testified about the attack before the House Intelligence Committee in 2012, about two months after the Benghazi attacks and shortly after revelations about his extra-marital affair with biographer Paula Broadwell. Petraeus resigned from the agency in the aftermath of the affair.

No committee members are expected to attend the Saturday session, only its lawyers and staffers.

Fox News' Chad Pergram contributed to this report.