Mike Pompeo, Doug Mastriano being interviewed by Jan. 6 committee: Sources

The House Jan. 6 committee was expected Tuesday to interview Donald Trump's former Secretary of State Mike Pompeo and Pennsylvania GOP gubernatorial nominee Doug Mastriano, sources familiar with the matter told ABC News.

ABC News first reported in July that Pompeo was in negotiations to sit with committee investigators behind closed doors. (CNN and The New York Times, respectively, first reported Mastriano and Pompeo's appearances before the panel.)

Mastriano has not agreed to the terms of his own closed-door interview with investigators. Mastriano's attorney wants to record the deposition or have access to the committee's recording after the fact. The committee has not agreed to that.

That has raised the possibility that in his virtual appearance, Mastriano may not answer questions or refuse to proceed. Mastriano has said he would walk out of a deposition with investigators if they didn't agree to his terms.

Mastriano, who has baselessly challenged the results of the 2020 election, was outside the Capitol on Jan. 6, 2021, but he has said he left when rioting broke out -- calling the violence "unacceptable."

His attorney previously told the Associated Press that he spoke with the FBI and "told them the truth about everything that happened that day."

The previous outreach to Pompeo, meanwhile, was an indication of the committee's continuing interest in gathering information and testimony from high-level Trump administration officials as the panel moved closer toward the release in the fall of a public report on its findings.

The committee's vice chair, Wyoming Republican Rep. Liz Cheney, said in late July that the group's work continued apace after wrapping its public hearings for the summer.

More hearings are expected related to the committee's report.

"We have a number of many interviews scheduled that are coming up. We anticipate talking to additional members of the president's Cabinet. We anticipate talking to additional members of his campaign," Cheney told CNN in July, adding, "We're very focused as well on the Secret Service and on interviewing additional members of the Secret Service and collecting additional information from them."

ABC News' Adam Carlson and Jonathan Karl contributed to this report.