Roger Stone, a longtime political adviser to Donald Trump, said in 2016 that he had had a conversation with WikiLeaks founder Julian Assange about senior Democrats’ emails, according to a new report from the Washington Post. Since the 2016 campaign, Stone has categorically denied he had contact with Assange or prior knowledge of the WikiLeaks documents.

According to the two Stone associates—one of whom was former Trump adviser Sam Nunberg—who told the Post about the conversation, Stone said Assange had told him he had emails in his possession that would embarrass John Podesta, who was the campaign chairman for Hillary Clinton. These emails, from Podesta and the Democratic National Committee, were obtained by hackers working from Russia, the U.S. intelligence community would later conclude.

Stone, who worked briefly for the Trump campaign and who was once so vulgar and misogynistic on Twitter that the platform permanently banned him, publicly claimed during the campaign that he had “communicated with Assange” and knew about an upcoming document leak. Since then, however, he has denied the conversation, as have WikiLeaks and Assange. He also told the Post he once made a joke to Nunberg when he called Stone on a Friday to ask about his weekend plans:

“I said, ‘I think I will go to London for the weekend and meet with Julian Assange.’ It was a joke, a throwaway line to get him off the phone. The idea that I would meet with Assange undetected is ridiculous on its face.”

According to Nunberg, investigators working for Robert Mueller asked him to describe the conversation Stone had with Assange. Federal investigators have during the course of their probe examined any potential contacts between Trump allies and WikiLeaks as possible evidence of collusion between the campaign and the Russians.

Stone communicated directly with WikiLeaks over private Twitter messages, the Atlantic reported in February. Stone described himself as a defender of WikiLeaks and told the organization to “figure out who your friends are” when WikiLeaks complained that Democrats were using “false claims of association” between them to undermine the organization.

The WikiLeaks documents, released in July and October of 2016, damaged the Clinton campaign and may have impacted the outcome of the presidential election.