Jérôme Corsi, a friend of Roger Stone, is in talks with Mueller

Asked about the pleadings on Friday, Mr. Stone replied, "My friend, Dr. Corsi, has been under tremendous pressure and this is starting to touch him deeply." Mr. Stone insisted, as he l? did I had at best only second-hand information about WikiLeaks' plans to disrupt the presidential race.

Among the other problems, investigators questioned a Twitter message of August 21, 2016 in which Mr. Stone had predicted that John D. Podesta, Clinton's campaign president, would soon face "his time in the barrel". Mr. Stone posted his message six weeks before WikiLeaks began to publish tens of thousands of emails from Mr. Podesta, putting the Clinton campaign on the defensive one month before the November elections.

Mr. Corsi publicly agreed with Mr. Stone's explanation of the message, saying that it predicted that Mr. Podesta would be controversial about his foreign business relations, and not about Stolen emails. "After reviewing my archives, I am now convinced that I am the source behind Stone's tweet," he wrote in an article published in early 2017 in Infowars, a site promoting conspiracy theories.

In a show broadcast on YouTube this month, Corsi said he has no inside information or links to Julian Assange, the founder of WikiLeaks. He compared the Special Council team to the Gestapo, saying that "they asked the same questions over and over again," until "my mind is not like before."

Like Mr. Stone, he said that he had mainly relied on public information to "compare points" on the role of WikiLeaks in the November elections. "If I remember correctly, nobody in the world has connected me to Julian Assange," he said in the YouTube video. "And what I knew in advance what Julian Assange was going to do, I understood."

"I guess I could not tell the special prosecutor what he wanted to hear," he said.

Mr. Mueller's team has laid charges against several people who misled federal investigators. Three former Trump campaign leaders or advisers pleaded guilty to this offense: Michael T. Flynn, Rick Gates and George Papadopoulos. The same was true for a Dutch lawyer, Alex van der Zwaan, who had business relations with Paul Manafort, former campaign chairman of Mr Trump.