Attorney Robert «Bob» Costello, once a legal adviser to Michael Cohen, told NBC News he will testify Monday before the Manhattan grand jury that will consider the case of former President Donald Trump on Monday.

Trump’s lawyers have asked District Attorney Costello to testify in the case involving a hush money payment to adult film star Stormy Daniels during the 2016 presidential campaign, according to a person with direct knowledge of the situation.

The news was first reported by the The New York Times.

Cohen, the former Trump attorney who pleaded guilty in federal court in 2018 to making the illegal payment to Daniels, testified before the grand jury last week. He, too, has met with prosecutors more than 20 times.

Cohen alleged that Trump ordered him to pay hush money for the «primary purpose of influencing» the 2016 presidential election. He told NBC News that he will return to the district attorney’s office Monday to prepare as a rebuttal witness.

The expected witness may contradict Cohen’s earlier testimony. Costello told NBC News on Sunday that he never signed a retainer agreement. He also said that Cohen waived attorney-client privilege in 2019, a move that surprised lawyers who took notice.

Cohen, meanwhile, said Costello never represented him.

A spokeswoman for the Manhattan district attorney’s office declined to comment.

The district attorney’s office has convened a grand jury to investigate the payment to Daniels, who alleges she slept with Trump before he became president. Trump has denied any wrongdoing and said he did not have an affair with Daniel. But he acknowledged that he paid Cohen back the $130,000, a payment he said was legal.

Tacopina said this month that Trump’s lawyers «have no plans» to meet with the district attorney’s office. And last week, Trump’s lawyer, Joe Tacopina, said that Trump will not appear before the grand jury.

NBC News reported Friday that law enforcement agencies are preparing for a possible impeachment of Trump starting next week. Following the report, Trump predicted in a post on his Truth Social social media platform on Saturday that he would be arrested on Tuesday and called on his supporters to protest.

The investigation is separate from the Justice Department’s investigation into Trump’s role in the Jan. 6 attack on the Capitol and his handling of classified documents, which is overseen by special counsel Jack Smith.