The House select committee investigating the Jan. 6, 2021, insurrection on Tuesday is set to interview former Secretary of State Mike Pompeo and the Donald Trump -backed GOP nominee for Pennsylvania governor Doug Mastriano, The New York Times reported .

The House panels work is separate from the criminal investigations pursued by the Department of Justice into Jan. 6 and an FBI raid of Trumps Mar-a-Lago residence on Monday.

Pompeo has reportedly been in talks with the Jan. 6 committee for some time about providing closed-door testimony as congressional investigators zero in on Trumps Cabinet.

The former secretary of state stuck with Trump even after rioters violently stormed the Capitol, and criticized those who resigned or sought to otherwise distance themselves from the then-president post-Jan. 6.

Cassidy Hutchinson, an aide to former chief of staff Mark Meadows, testified publicly that Pompeo contacted Meadows following Capitol riot to inform him of discussions within the Cabinet of invoking the 25th Amendment to remove Trump from office.

Mastriano, an extremist state senator who joined Trumps effort to overturn the 2020 presidential election, has been arguing with the committee over whether his lawyer would be allowed to videotape his testimony or get a recording of Mastrianos deposition later, according to CNN .

Senator Mastriano has nothing to hide and would be happy to answer their questions, defense lawyer Timothy C. Parlatore told the Times. Our only concern is to prevent the committee from releasing misleading and edited portions while keeping the proper context hidden. Either release the entirety or let me make a copy and we have no issue.

Parlatore told CBS News his clients appearance will be short.

Mastriano reportedly used campaign funds to pay Parlatore to represent him.

The state senator, who was at the U.S. Capitol during the insurrection, was subpoenaed by the Jan. 6 committee in February for his participation in Trumps fake electors scheme.

We understand that you have knowledge of and participated in a plan to arrange for an alternate slate of electors to be presented to the President of
the Senate on January 6, 2021, and we understand that you spoke with former President Trump about your post-election activities, a letter addressed to Mastriano reads.

The committee told Mastriano they want to hear more about the theories behind his election fraud allegations.

We understand you participated in these activities based on assertions of voter fraud and other asserted irregularities and based on a stated belief that under
the U.S. Constitution the state legislature has the sole authority to direct the manner of selecting delegates to the Electoral College. We have an interest in understanding these activities and the theories that motivated them, the letter continues.

In response to the subpoena, Mastriano produced some documents related to the insurrection, including a passenger list showing his campaign sold over 130 tickets to the Stop the Steal rallies that preceded the Capitol riot, and social media posts, according to Politico .