The documents are heavily redacted and feature some of the headline names from the two-year Mueller investigation, including Michael Cohen, Trump’s former lawyer and fixer, and former Trump campaign chairman Paul Manafort, both of whom are currently serving federal prison sentences.

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In one document, former White House chief strategist Stephen Bannon refers to Manafort in an November 5, 2016, email to Jared Kushner, Trump’s son-in-law, days before the presidential election and months after Manafort supposedly parted ways with the campaign.

“We need to avoid this guy like the plague,” Bannon wrote to Kushner.

“They are going to try and say the Russians worked with WikiLeaks to give this victory to us. Paul is a nice guy but can’t let word get out he is advising us.”

Manafort had started the email string on the subject of “Securing the Victory”, telling Kushner that he was “really feeling good about our prospects”.

Fox News host Sean Hannity was also mentioned in Manafort’s note and in other documents.

Another revelation from the cache was a reflection made to the FBI by Rick Gates, Trump’s former deputy campaign chair, about then-candidate Trump’s infamous comment about Russia in July 2016.

“Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Trump said, referring to Hillary Clinton’s deleted messages.

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The remark was an ad lib, Gates contended. The same document showed Gates remembering staff conversations that “someone out there” must have the missing Clinton emails.

Gates also said Manafort had offered the theory that Ukraine, not Russia. was behind a June 2016 hack on the Democratic National Committee computers.

That idea, which has been discredited by US intelligence agencies, is still pushed by Trump and others, and has become central to the current Democratic impeachment inquiry into the president.

The House of Representatives current impeachment probe of the president is looking at whether Trump improperly pressured Ukraine President Volodymyr Zelensky to investigate his political rival, former US vice-president Joe Biden, in a July phone call.

In that call, Trump pressed the Ukrainian president to investigate possible Ukraine involvement in the 2016 election email hacking.

In another document posted by BuzzFeed, drawn from the summary of Bannon’s interview with the FBI, the former Goldman Sachs investment banker recalled having first met Trump in 2010. Conservative activist David Bossie, president of Citizens United, was also present, and said that Trump was thinking of running for president in 2012.

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According to the recap, Bannon asked: “for what country?”

After making requests through the Freedom of Information Act, BuzzFeed and CNN sued the US government for the right to see the primary-source information that Mueller’s team didn’t disclose when it published its 448-page report in March.

Justice Department lawyers say the material could run to 18 billion pages.

The process of releasing all the documents monthly will probably take eight or more years.

Additional reporting by Reuters