WASHINGTON — Conspiracy theorist Jerome Corsi indicated he had advanced knowledge about the release of hacked emails by WikiLeaks ahead of the 2016 election, according to documents obtained by CBS News.

"Word is friend in embassy plans 2 more dumps," Corsi wrote in an email to Roger Stone, President Trump's sometime political adviser, on Aug. 2, 2016. "One shortly after I'm back. 2nd in Oct. Impact planned to be very damaging."

The "friend in embassy" is WikiLeaks founder Julian Assange, who has spent years camped out in the Ecuadorean Embassy in London to avoid extradition. In the lead up to the 2016 election, WikiLeaks published thousands of pages of emails that were hacked by Russian agents from Democratic computers. Many Democrats say these email dumps affected the outcome of the election.

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In his Aug. 2 email to Stone, Corsi said it's "time to let more than [Hillary Clinton campaign chairman John Podesta] to be exposed as in bed [with] enemy if they are not ready to dump [Clinton]." WikiLeaks began releasing the hacked Democratic emails Oct. 7, 2016.

Jerome Corsi, seen in a 2008 file photo. Corsi, a conservative writer and associate of President Donald Trump confidant Roger Stone, says he is in plea talks with special counsel Robert Mueller's team. AP

The documents, known as a statement of offense, were sent to Corsi by the office of special counsel Robert Mueller. Mueller and his team are investigating Russian interference in the 2016 election, and U.S. officials have accused WikiLeaks of being a cutout for Russian intelligence.

NBC News first reported the existence of the documents, which say Corsi has been cooperating with Mueller's investigation since Sept. 6. According to Corsi, Stone told him to get in touch with Assange and WikiLeaks in the summer of 2016 and "get the pending emails."

According to the documents, Corsi lied to investigators and said he rebuffed Stone, when he instead passed along the request to someone living in London. Corsi also began deleting emails to and from Stone early in 2017, although he continued to stay in touch with Stone as the investigation into Russian interference took shape.

After Stone told congressional investigators that radio host Randy Credico had been his "intermediary" with WikiLeaks, Credico was subpoenaed to testify before the House Intelligence Committee. When Stone learned of this, he asked Corsi to write about Credico.

"Are you sure you want to make something out of this now?" Corsi replied. "Why not wait to see what [Credico] does? You may be defending yourself too much — raising new questions that will fuel new inquiries. This may be a time to say less, not more."

Stone responded Credico would invoke his Fifth Amendment rights, "but let's hold a day."

The documents also include a draft plea agreement for Corsi, who says he refuses to sign it.

Julia Kimani Burnham and Clare Hymes contributed reporting to this story.