The House select committee investigating the events surrounding Jan. 6, 2021, is trying to fill in an hourslong gap in White House call logs on the day a pro-Trump mob attacked the U.S. Capitol, lawmakers said.

The committee is looking into the possibility that Mr. Trump used a disposable burner phone that wouldn’t have shown up in call logs. The Washington Post and CBS News jointly reported that records obtained by the committee show a more than 7-hour gap in former President Donald Trump’s phone logs on Jan. 6, from 11:17 a.m. to 6:54 p.m. The existence of a gap in the logs had been previously reported.

Rep. Pete Aguilar of California, a member of the committee and House Democratic leadership, said at a press conference Tuesday that there are “quite a few gaps” within Mr. Trump’s schedule that the 9-member committee is trying to fill, along with details about funding and planning for the “Stop the Steal” rally earlier in the day. At the rally, Mr. Trump falsely claimed that President Biden had stolen the 2020 election and urged his followers to march on the Capitol.

“One possibility, when a gap like this exists, is that the president or whomever we’re looking at is using a different phone,” Rep. Jamie Raskin (D., Md.), also a member of the committee, said on MSNBC. He said there is a possibility that someone is deliberately suppressing the release of the call logs and other materials sought by the committee.