House speaker Nancy Pelosi on Thursday accused Attorney General William Barr of lying to Congress in April testimony before the House Appropriations Committee.

“We saw [Barr] commit a crime when he answered your question,” Pelosi is said to have told Representative Charlie Crist during a closed-door meeting Thursday.

Crist, a Florida Democrat, had asked Barr during an April Appropriations Committee whether he knew what news reports that members of Special Counsel Robert Mueller’s team were dissatisfied with his four-page summary of its final report were referring to. Barr said that he was not, an answer seemingly contradicted by subsequent reports that he’d previously received a letter from Mueller and spoken with the special counsel over the telephone about investigators’ concerns with the summary.

Asked about the contradiction in testimony before the Senate Judiciary Committee on Wednesday, Barr stood by his response, saying that Mueller did not call his summary of the final report inaccurate but merely was unhappy with the press coverage of it.

“Attorney General Barr’s decision to mislead the public in his testimony to Congress was not a technicality — it was a crime,” Pelosi added later in a tweet.

“It’s called perjury,” Crist said of Barr’s statements. “We ought to have somebody who is in a law-enforcement space charge him.”

Barr canceled his planned appearance before the House Judiciary Committee Thursday, frustrating Democrats, some of whom have called on him to resign or be impeached. Judiciary Committee chairman Jerry Nadler said he may hold Barr in contempt of Congress should the Justice Department follow through on its threat to ignore the Committee’s subpoena of the unredacted report and underlying evidence.