Michael Cohen, President Donald Trump’s former personal lawyer and fixer, acknowledged Wednesday that he is aware of potential crimes committed by the president that are unknown to the public and are under investigation by federal prosecutors in New York.

That reveal, which lit up social media, came during questioning by Illinois Rep. Raja Krishnamoorthi, a Schaumburg Democrat who is a member of the U.S. House Oversight and Reform Committee. That committee spent much of the day hearing testimony from Cohen.

“Is there any other wrongdoing or illegal act that you are aware of regarding Donald Trump that we haven’t yet discussed today?” Krishnamoorthi asked Cohen.

“Yes, and again those are part of the investigation that’s currently being looked at by the Southern District of New York,” Cohen answered.

That exchange marked one of the morning’s highlights from the highly anticipated Cohen appearance before the congressional panel, which was looking to uncover more detail about possible crimes involving Trump.

“My guess is President Trump and his lawyers are probably trying to figure out what this other investigation is about,” Krishnamoorthi later told WBEZ.

In his questioning, Krishnamoorthi also sought to pin down when Cohen last spoke with the president. Cohen answered that it was at some point last fall. He also said the topic of that conversation was not something he could divulge because it, too, is under investigation by federal prosecutors in New York.

Even though Republicans tried to poke holes in Cohen’s testimony, noting he had pleaded guilty to an earlier charge of lying to Congress, Krishnamoorthi said he found Cohen’s appearance to be believable.

“He comes across as credible,” the congressman said in an interview with WBEZ. “He has good answers to the questions.”

Earlier in his testimony, Cohen called Trump a “racist,” a “con man ” and a “cheat” and said Trump implied that Cohen should lie to Congress about a Moscow real estate project the president’s company was pursuing during the 2016 election.

Cohen also outlined alleged bigotry on the part of the president and specifically cited one instance when he was traveling with Trump through an undisclosed, mostly African-American neighborhood in Chicago.

“While we were once driving through a struggling neighborhood in Chicago, he commented that only black people could live that way. And, he told me that black people would never vote for him because they were too stupid,” Cohen told the panel.

While there was no statement from the White House Wednesday about Cohen’s testimony, President Trump used his Twitter account to denounce his onetime lawyer, saying Cohen “did bad things unrelated to Trump. He is lying in order to reduce his prison time.”

Cohen faces three years in federal prison and is scheduled to begin serving that time in May after having pleaded guilty to multiple criminal counts, including lying to Congress.

Dave McKinney covers state politics and government for WBEZ. Follow him @davemckinney.