Michael Cohen was once former President Donald Trump’s right-hand man.

Now, he’s the star cooperator in Manhattan District Attorney Alvin Bragg’s case against Trump.

In a sign of Bragg’s readiness to seek an indictment, Cohen testified Monday before a grand jury.

He addressed reporters before entering the courthouse.

“This is not revenge, right? What this is about is accountability,” Cohen said. “I don’t want to see anyone, including Donald Trump, indicted, prosecuted, convicted, incarcerated, simply because I fundamentally disagree with them. This is all about accountability. He needs to be held accountable for his dirty deeds.”

Manhattan prosecutors’ probe revolves around the allegation that Trump paid $130,000 in hush money to adult film actress Stormy Daniels to keep news of their affair from coming out during his 2016 campaign.

Trump himself was invited to testify before the grand jury.

On Monday, his attorney responded on ABC News’ “Good Morning America.”

“We have no plans on participating in that proceeding,” Joseph Tacopina said.

Trump, now a 20-24 contender, has denied the affair.

He has had choice words for Cohen, his former attorney.

And Trump’s current attorney, Tacopina, effectively accused Bragg and his fellow prosecutors of a witch hunt.

“This case is outrageous,” Tacopina told ABC News. “Really, there should be a healthy dose of disgust from the bar, the legal community, prosecutors, defense lawyers alike.”

On Monday, Tacopina also issued a 12-page letter to the city Department of Investigation, asking that it probe whether Bragg, his team and his predecessor “improperly weaponized their office for political gain.”

The DOI declined to comment.

The New York Times reported that the grand jury has already heard from more than a half dozen other witnesses.

Trump could face a misdemeanor charge of falsifying business records or, less likely, felony intent to commit or conceal a second crime.