WASHINGTON (Reuters) – U.S. President Donald Trump’s son-in-law, Jared Kushner, met with Special Counsel Robert Mueller’s team earlier this month as part of its Russia probe, CNN reported on Wednesday, citing two people familiar with the meeting.

Former White House national security adviser Michael Flynn was the prime topic of the conversation between Kushner and Mueller’s team, CNN said, citing one of the sources.

Flynn, who resigned in February after misleading Vice President Mike Pence about his conversations with a Russian diplomat, is under investigation by Mueller’s team, which is looking into possible collusion between Russia and the Trump campaign in last year’s presidential election.

The nature of the questioning was principally to make sure Kushner did not have information that exonerated Flynn, CNN said, citing one source.

Kushner spoke with Mueller’s team for less than 90 minutes, CNN said.

“Mr. Kushner has voluntarily cooperated with all relevant inquiries and will continue to do so,” Abbe Lowell, Kushner’s lawyer, told Reuters.

Lawyers for Flynn have halted communications with Trump’s legal team, a potentially critical step in Mueller’s probe, sources familiar with the investigation said on Friday.

Flynn’s lawyer, Robert Kelner, called John Dowd, Trump’s private lawyer, last week to say the matter had reached a point where the two could no longer could discuss it, two people familiar with the call told Reuters.

It was not clear whether Kelner made the call because he had negotiated a plea agreement with Mueller for Flynn to cooperate in the probe, or because Flynn had decided to engage with Mueller, said two other sources.

The probe has dogged the White House since January, when U.S. intelligence agencies concluded that Russia interfered in the election to try to help Trump defeat Democrat Hillary Clinton by hacking and releasing embarrassing emails and disseminating propaganda via social media to discredit her.

Russia has denied interfering in the U.S. election and Trump has said there was no collusion.