The controversial Jerome Corsi, who is connected to President Trump and political consultant Roger Stone, has gotten caught up in Special Counsel Robert Mueller’s investigation.

He said Friday he was negotiating a potential plea deal with investigators, according to reports from The Washington Post and The Associated Press. Thus far, four former Trump campaign associates – Michael Flynn, Paul Manafort, Richard Gates and George Papadopoulos – have been charged as a result of the probe, although none of the charges is directly related to any misconduct by the president’s campaign.

Manafort was the first to have been found guilty by a jury trial.

Mueller’s team has reportedly questioned Corsi in regards to Stone’s connections with WikiLeaks. American intelligence agencies have assessed that Russia was the source of hacked material released by WikiLeaks during the 2016 election that damaged Hillary Clinton's campaign. Mueller's office is trying to determine whether Stone and other Trump associates had advance knowledge of WikiLeaks' plans.

Here’s what to know about Corsi.

He’s an author and conspiracy theorist

The former Infowars Washington bureau chief, Corsi is known for peddling conspiracy theories – particularly the false claim that former President Barack Obama was not born in the U.S. In fact, Trump reportedly contacted Corsi before he became a presidential candidate to inquire about the conspiracy theory, according to The New York Times.

He’s the author of “The Obama Nation” and co-author of “Unfit for Command,” highly scrutinized books attacking the former president and former Sen. John Kerry, respectively. In his book about Kerry, he alleged the then-presidential candidate was dishonest about his Vietnam military service.

He also authored another book, “Where’s the Birth Certificate?”, in which he attempts to make the case that Obama could not constitutionally be president.

He’s peddled conspiracies about the 9/11 terrorist attacks and accused former President George W. Bush of wanting to do away with the Canadian and Mexican borders.

He already said he expects to be charged in Mueller probe

Corsi said last week that he expected an indictment was forthcoming and was issued subpoenas by the FBI just before his 72nd birthday. He had already been questioned by Mueller’s team as part of a probe into Stone’s connections with WikiLeaks, according to The Associated Press.

“I fully anticipate that in the next few days I will be indicted by Mueller for some form or other of giving false information to the special counsel or to one of the other grand jury – or however they want to do the indictment,” Corsi said during a livestream video. “But I’m going to be criminally charged.”

“This has been one of the most frightening experiences of my life. At the end of the two months, my mind was mush,” he added.

Corsi said his only “crime” was his support of Trump. He added that he’s afraid he will go to jail “for the rest of my life because I dared to oppose the deep state.”

He reportedly turned over two computers and a cell phone to investigators and gave the FBI access to his email and Twitter accounts.

He holds a Ph.D. from Harvard

Corsi graduated from Harvard University in 1972 with a Ph.D. in political science, according to his Simon & Schuster biography.

He reportedly considered a presidential bid as the Conservative Party nominee in 2008.

The Associated Press contributed to this report.