Former Speaker Newt Gingrich (R-Ga.) testified Thursday before a federal grand jury investigating the Jan. 6 attack on the Capitol, according to CNN.

The former House committee that investigated the Jan. 6 riot alleged last September that Gingrich had provided feedback to the Trump campaign about advertisements promoting the former president’s unsubstantiated claims about voter fraud and discussed “coordinating” state electors.

In a letter to the former Speaker requesting a voluntary interview, the committee said that Gingrich communicated with former Trump senior advisers Jared Kushner and Jason Miller on campaign ads about the election, after it had been declared for Joe Biden.

The ads Gingrich advised on had “encouraged members of the public to contact their state officials and pressure them to challenge and overturn the result of the election” in the days before state electors would cast their votes, the letter said.

The committee also suggested Gingrich was “involved in the fake elector scheme,” pointing to a November 2020 message to former White House chief of staff Mark Meadows and former White House counsel Pat Cipollone.

“Is someone in charge of coordinating all the electors?” the message read. “Evans makes the point that all the contested electors must meet on [D]ecember 14 and send in ballots to force contests which the house would have to settle.”

Gingrich had previously been ordered to testify before a special grand jury investigating election interference in Georgia. However, the former Speaker’s case to block the testimony was ultimately dismissed in February after the Fulton County grand jury concluded its work.