Rudy Giuliani, a one-time lawyer for former President Trump, testified virtually on Friday before the House select committee investigating the attack on the U.S. Capitol, two sources familiar with the matter told CBS News.

Giuliani testified virtually for over nine hours, the sources told CBS News. His attorney, Robert Costello, did not respond to requests for comment.

Giuliani was subpoenaed by the committee in January 2022, along with Jenna Ellis and Sidney Powell, two lawyers who worked to promote former President Trump’s false claims about the election, and Boris Epshteyn, a former Trump White House aide.

The four figures participated in a November 19, 2020, press conference that featured baseless claims the election had been stolen and that Trump had won in a “landslide.”

A spokesperson for the committee said earlier this month that Giuliani is an “important witness to the conspiracy to overthrow the government.”

He backed out of a scheduled appearance earlier this month, Tim Mulvey, a spokesperson for the committee, said on May 6. According to Mulvey, Giuliani refused to appear unless he could record the interview.

Giuliani is the latest witness to appear before the committee as it winds down its investigation and prepares for public hearings, set to start on June 9.

Chairman Bennie Thompson told CBS News last month the committee had been in talks with Giuliani and remained hopeful that he would eventually cooperate.

“We’ve been talking primarily to a lot of people and he’s one of them,” Thompson said.

House Speaker Nancy Pelosi created the House select committee last year to investigate the January 6 attack, when thousands of Trump supporters descended on the Capitol as Congress counted the electoral votes, a largely ceremonial final step affirming Mr. Biden’s victory. Lawmakers were sent fleeing amid the riot, which led to the deaths of five people and the arrests of hundreds more.

Trump, who encouraged his supporters to “walk down” to the Capitol during the rally at the Ellipse before the electoral vote count, was impeached by the House one week later for inciting the riot but was later acquitted by the Senate.

The committee has issued dozens of subpoenas, including ones to Trump’s allies, former White House officials, campaign aides and individuals involved in the planning of the rally outside the White House before the Capitol building came under siege. Two top Trump allies, Steve Bannon and former White House chief of staff Mark Meadows, have been held in contempt of Congress for refusing to comply with subpoenas, and the Justice Department has charged Bannon. Both said they are following instructions from Trump, who has claimed executive privilege.