Conservative author Jerome Corsi said Monday that he expects to be indicted by prosecutors working for special counsel Robert S. Mueller III on a charge of lying to investigators probing Russian interference in the 2016 campaign.

Corsi, a writer who has promoted political conspiracy theories, provided research during the White House race to longtime Trump adviser Roger Stone, who Mueller has been scrutinizing for possible ties to WikiLeaks.

On Monday, Corsi told listeners of his daily live-stream Web program that he turned over two computers, emails and other communications to Mueller and sat for six interviews totaling more than 40 hours since receiving a subpoena two months ago.

But he said that his cooperation had “exploded” in recent weeks and that Mueller’s team has said he will be criminally charged.

On Feb. 20, 2020, Roger Stone was sentenced to three years and four months in prison. President Trump commuted Stone’s sentence on July 10, 2020. (Monica Akhtar, Erin Patrick O'Connor/The Washington Post)

“I’m going to be indicted. That’s what we’ve been told. Everyone should know that,” he said.

After two months of interviews, Corsi, 72, said he felt his brain was “mush.”

“I anticipate being indicted on a charge of some form of lying,” he said. “Trying to explain yourself to these people is impossible . . . I guess I couldn’t tell the special prosecutor what he wanted to hear.”

He said that Mueller’s questions were expansive, including about a trip he took with his wife to Italy before the 2016 election. Corsi added that he believes Mueller’s team is persecuting him because of his outspoken opposition to the investigation and defense of President Trump.

“The Department of Justice is run by criminals,” Corsi said, adding: “I think my crime really was that I supported Donald Trump. Now I guess I’ll go to prison for the rest of my life, because I dared to oppose the ‘deep state.’ ”

A spokesman for the special counsel’s office declined to comment.

Corsi did not tell his viewers precisely what he had been told by special counsel prosecutors, but made an appeal for donations to his legal defense fund. His attorney, David Gray, declined to comment.

Corsi is one of at least nine Stone associates who have been interviewed by Mueller’s team, which has been investigating whether anyone in Trump’s orbit coordinated with WikiLeaks in its release of Democratic emails allegedly hacked by Russian operatives.

Stone made public comments before the 2016 election that suggested he had inside information about material held by WikiLeaks and its founder Julian Assange.

Since the election, Stone has said repeatedly that his comments were exaggerations or came from tips from associates, and that he had no advance knowledge of WikiLeaks’s plans.

In a text message to The Washington Post on Monday, Stone said he has not been contacted by Mueller’s team. He said that his attorneys have “fully reviewed” his communications with Corsi.

“When those aren’t viewed out of context, they prove everything I have said under oath regarding my interaction with Dr. Corsi is true,” Stone said, adding: “It is possible to take individual communications out of context to create a false impression to a grand jury. Such a case would be weak and would fail.”

Appearing on the Infowars website Monday evening, Stone said that “perhaps they have squeezed poor Dr. Corsi to frame me.”

Stone also seemed to lay the groundwork for an effort to undercut Corsi’s credibility as a witness. “He has his own demons,” Stone said of Corsi.

Previously, Stone has said one of his most intriguing pre-election comments was inspired by Corsi.

On August 21, 2016, Stone tweeted that “it will soon the Podesta’s time in the barrel.” Six weeks later, WikiLeaks began to publish online emails hacked from the account of John Podesta, the chairman of Democratic nominee Hillary Clinton’s campaign.

Stone has said his tweet had nothing to do with WikiLeaks.

Instead, he has said he was referring to research material he had discussed with Corsi about links between Russia and John Podesta and his brother, lobbyist Tony Podesta.

Corsi has said also said he believes Stone’s tweet was prompted by his research.

On his live-stream program Monday, Corsi said he had never met Assange and had no connection to him. “To the best of my recollection,” he added.

He said that to the extent that he had advance knowledge of WikiLeaks’s plans, he had surmised the group’s intentions on his own.

“There was no conspiracy,” Corsi said. “I found out what I knew largely from open sources. “ He promised to share more details in coming days.

Stone has previously told The Post that Corsi developed a relationship with Trump over their shared interest in the false theory that President Barack Obama was not born in the United States, the subject of a 2011 Corsi book.

Corsi and Trump met during the 2016 campaign, according to Stone.

Stone recalled that Trump asked him around that time, ‘Who is this guy, Jerome Corsi?’ ” Trump then informed Stone that he had been discussing the subject of Obama’s birth certificate with Corsi.