Michael Cohen, former trusted aide and lawyer to President Donald Trump, testifies before the House Oversight and Reform Committee on Capitol Hill in Washington DC on Wednesday February 27, 2019.

An attorney for Michael Cohen raised the idea of a pardon with President Donald Trump's lawyers after federal authorities raided Cohen's residence and office in April, The Wall Street Journal reported, citing people familiar with the talks.

Congress is now investigating those conversations, documents requested by the House Judiciary Committee revealed on Monday, the Journal said.

The pardon discussions happened as Cohen's attorney at that time, Stephen Ryan, was working with Trump's lawyers to determine whether documents seized by the FBI during the April raid were protected by attorney-client privilege, sources told the Journal.

The report comes days after Cohen told lawmakers on Capitol Hill last week that he never asked for a pardon from Trump, and that he would not accept one. The Journal article noted there was no evidence that Cohen himself asked for a pardon or was aware of the alleged pardon discussions.

Trump's lawyers – including Jay Sekulow, Rudy Giuliani and Joanna Hendon – dismissed the idea of a pardon at the time, the sources said, according to the Journal. But the paper also reported that Giuliani left open the possibility of an eventual presidential pardon.

Ryan also approached attorneys for the Trump Organization, the president's company, about a pardon, the Journal reported. Ryan no longer represents Cohen in the criminal case.

If a pardon was not an option, Ryan left the impression that his client Cohen might flip and cooperate with investigators from the Manhattan U.S. attorney's office, the paper added.

Ryan and a spokesperson for Giuliani did not return CNBC's requests for comment.

A spokeswoman for Cohen told CNBC in an email, "Mr. Cohen stands by his testimony before the House Oversight Committee."

In August, Cohen pleaded guilty to eight charges, including two campaign finance violations for arranging hush money payments during the 2016 campaign to two women – porn star Stormy Daniels and Playboy model Karen McDougal – who alleged they had sexual trysts with Trump a decade earlier. Trump has denied the affairs.

Cohen also pleaded guilty to lying to Congress. He will report to prison May 6, when he is slated to begin a three-year sentence.

Read the full Journal article here.