Christopher Miller, who was acting secretary of defense during the Jan. 6 riot, met Friday with members of the House committee investigating the origins of the attack on the Capitol, a source familiar with the panel's activities told NBC News.
The meeting came as the committee ramps up its probe, issuing more subpoenas and requesting several GOP lawmakers voluntarily testify.
It was not immediately clear what Miller discussed with the panel. The former Pentagon chief has provided conflicting testimony to Congress in the past, at one time saying that former President Donald Trump had "encouraged the protesters" with his remarks on Jan. 6 and then later saying he believed an "organized conspiracy" played a role in the Capitol attack.
In December, the panel met with Kash Patel, who was Miller's chief of staff at the Pentagon and a former top aide to Rep. Jim Jordan, R-Ohio.
The committee in recent weeks has sought to speak with numerous Trump allies, former administration officials and Republican lawmakers. Some have complied with subpoenas, while others have said they will not cooperate with the committee.
The Department of Justice has brought charges against more than 700 alleged participants in the Jan. 6 riot. More than 100 Capitol Police officers reported being injured in the melee.
On Thursday Elmer Stewart Rhodes, founder of the far-right militia group the Oath Keepers, was indicted alongside 10 others, for "seditious conspiracy and other charges for crimes" related to the breach of the Capitol, the Justice Department said.