WASHINGTON (AP) — The congressional committee investigating the U.S. Capitol insurrection is asking a House Republican for more information about a tour of the complex that the panel says he led the day before the deadly attack.

The committee's letter to Georgia Rep. Barry Loudermilk on Thursday is the latest attempt by House investigators to obtain cooperation from GOP lawmakers in the probe of the Jan. 6, 2021 attack, Supporters of then-President Donald Trump violently broke into the Capitol that day and interrupted the certification of President Joe Biden's victory.

"Based on our review of evidence in the Select Committee's possession, we believe you have information regarding a tour you led through parts of the Capitol complex on January 5, 2021," wrote Reps. Bennie Thompson of Mississippi and Liz Cheney of Wyoming, the chairman and vice-chairwoman of the committee.

"Public reporting and witness accounts indicate some individuals and groups engaged in efforts to gather information about the layout of the U.S. Capitol, as well as the House and Senate office buildings" in advance of the insurrection, they wrote.

The voluntary request comes as the panel has already conducted more than 1,000 interviews about the insurrection and as it prepares for a series of hearings in June. The questions about tours of the Capitol ahead of the attack have lingered since the days afterward, when Democrats suggested that some Republican members may have helped the rioters. But so far there has been no public evidence of that assistance.

The letter to Loudermilk said that Republicans on a separate panel, the House Administration Committee, had previously said they reviewed security footage from Jan. 5 and said there were "no tours, no large groups, no one with MAGA hats on." Loudermilk is a member of that panel.

But the Jan. 6 committee's review of the evidence "directly contradicts that denial," Thompson and Cheney wrote.

That earlier assessment by GOP members came after three dozen Democrats sent a letter to the committee days after the attack citing alleged sightings of "unusually large" groups led by either Republican lawmakers or their staff in the days leading up to the attack.

In a statement Thursday, Loudermilk said the Jan. 5 tour was with a constituent family and took place in the House office buildings and not inside the Capitol building itself

"We call on Capitol Police to release the tapes," Loudermilk and Rep. Rodney Davis, R-Ill., the ranking member of the House administration committee, wrote in a joint response to the letter.

The Capitol complex includes 20 buildings and facilities, including House and Senate offices. Underground tunnels connect most of the buildings to the Capitol.

The request comes a week after the panel issued subpoenas to five Republican members, including Minority Leader Kevin McCarthy.

The decision to issue subpoenas to McCarthy, R-Calif., and Reps. Jim Jordan of Ohio, Scott Perry of Pennsylvania, Andy Biggs of Arizona and Mo Brooks of Alabama was a dramatic show of force by the panel, which has already interviewed nearly 1,000 witnesses and collected more than 100,000 documents as it investigates the worst attack on the Capitol in two centuries.

The five Republicans, all of whom have repeatedly downplayed the investigation's legitimacy, have yet to say whether they will comply.

In total, the committee has now publicly requested cooperation from at least eight lawmakers it believes have information crucial to the planning and execution of the attack and former President Donald Trump's potential role in inciting it.

This story was first published on May 19, 2022. It was updated on May 24, 2022 to make clear that the Capitol complex includes 20 buildings and facilities.