WASHINGTON — The House January 6 panel is calling a surprise hearing this week to present evidence it says it recently obtained, raising expectations of new bombshells in the sweeping investigation into the Capitol riot.

The hearing scheduled for 1 p.m. on Tuesday comes after Congress left Washington for a two-week recess. Lawmakers on the panel investigating the January 6, 2021, attack said last week that there would be no more hearings until July.

The subject of the hearings is so far unclear. A spokesman for the panel declined to comment on its substance.

The committee’s investigation has been ongoing during the hearings that started three weeks ago, and the nine-member panel has continued to probe the attack by supporters of President Trump. Among other investigative evidence, the committee recently obtained new footage of Mr. Trump and his inner circle taken both before and after January 6, 2021, from a British filmmaker, Alex Holder.

Mr. Holder said last week that he had complied with a congressional subpoena to turn over all of the footage he shot in the final weeks of Mr. Trump’s 2020 re-election campaign, including exclusive interviews with Mr. Trump, his children, and Vice President Pence while on the campaign trail. The footage includes material from before the January 6 riot and afterward.

It is uncertain if Mr. Holder’s footage is the subject of the hearing on Tuesday, or if Mr. Holder himself will be there. A lawyer for Mr. Holder, Russell Smith, declined to comment.

The panel’s Democratic chairman, Congressman Bennie Thompson, told reporters last week that the committee was in possession of the footage and needed more time to go through the hours of video footage Mr. Holder had turned over. The British filmmaker came in for a deposition Thursday that lasted two hours, Mr. Smith said last week.

Mr. Smith said then that it was Mr. Holder’s “civic duty” to come forward and that the footage had shown some inconsistencies with previous testimony during the hearings.

The panel has held five hearings so far, mostly laying out Mr. Trump’s pressure campaign on various institutions of power in the weeks leading up to the January 6 joint session of Congress that eventually certified President Biden’s victory. The committee detailed the pressure from Mr. Trump and his allies on Mr. Pence, on the states that were certifying Mr. Biden’s win, and on the Justice Department.

The panel has used live interviews, video testimony of its private witness interviews, and also footage of the attack to detail what it has learned.

Lawmakers said last week that the two July hearings would focus on domestic extremists who breached the Capitol that day and on what Mr. Trump was doing as the violence unfolded.