(CNN) Roger Stone exchanged text messages with his alleged WikiLeaks back channel about imminent "big news" harmful to Hillary Clinton's campaign six days before WikiLeaks released hacked emails from former Clinton campaign chairman John Podesta, according to new messages released by Stone.

"big news Wednesday," Randy Credico, a progressive New York political activist and radio host, texted Stone on October 1, 2016. "now pretend u don't know me."

"U died 5 years ago," Stone, a longtime ally of President Donald Trump, responded.

"great," Credico texted back. "Hillary's campaign will die this week."

Stone provided the text messages in an effort to prove Credico was his source of information on WikiLeaks. The text messages appear to show Credico providing Stone with updates on Julian Assange, the founder of WikiLeaks, and his document-dump plans just ahead of their public release in October. In some of the texts, Credico appears to indicate he has insights into Assange's plans through Assange's lawyer.

Credico's messages came the same week Assange scheduled a news conference with much fanfare, promising an October surprise. Assange didn't deliver any dirt on Clinton during the press event, much to the dismay of her critics.

But days later, on October 7, WikiLeaks released the first batch of emails hacked from Podesta's personal account soon after The Washington Post published audio of Trump making disparaging remarks about women. The group would go on to release near-daily hacked emails in the closing weeks of the presidential race, altering the course of the campaign.

Stone has been a focus of special counsel Robert Mueller, who is investigating Russian interference in the 2016 presidential election and whether anyone from Trump's campaign was involved. Mueller is looking into Stone's potential back channels to WikiLeaks and his communication with then-candidate Trump during the campaign as part of the probe.

Grant Smith, Stone's attorney, provided CNN with copies of the messages, which were first reported by NBC News. "I think these are completely vindicating of Roger," Smith said. "It could not be any clearer."

On August 27, 2016 -- just days after Credico interviewed Assange for a radio show -- Credico texted Stone, "Julian Assange has kryptonite on Hillary."

While Stone made a number of public claims in 2016 that seemed to suggest he had advance warning of WikiLeaks' plans, he has denied having early knowledge of hacked messages that could be damaging to Clinton's presidential bid. He has said his statements during the campaign were based on public information and his back channel, Credico.

Credico denied that he acted as Stone's intermediary with WikiLeaks and said his messages to Stone were based on Assange's public statements.

"It's two observers to a potential dump by Julian Assange. That's it," Credico told CNN.

Credico also accused Stone of cherrypicking the messages he released.

"He's retroactively trying to invent something to cover his a--," Credico said.

Credico has been interviewed multiple times by Mueller's investigators and has testified before the grand jury. He noted that he has handed all of his communications with Stone over to the special counsel. Credico said he also gave investigators permission to retrieve messages from his cell phone provider that were no longer available on his devices.

Credico's attorney said Wednesday that he believed Mueller's investigators were finished questioning his client. After the latest text message release Wednesday, Credico said he wouldn't be surprised if Mueller's team followed up with additional questions.

Stone and Credico have a complicated history that spans more than a decade. Over the years, they've worked together on political campaigns and called each other friend. But it has been a rocky relationship, and at one point years ago, Stone started a rumor that Credico was dead.

In the released text messages, Credico repeatedly asks Stone not to name him as his connection to Assange. "Just remember do not name me as your connection to Assange you had one before that you referred to," he texted Stone on September 18, 2016.

Credico also texts Stone selfies taken outside of what appears to be the Embassy of Ecuador in London, where Assange has taken refuge, days before Assange held his Oct. 4 news conference promising the big reveal. Credico said he never made it inside the embassy on his trip.