Sen. Ron Wyden (D-Ore.) on Tuesday called on the Biden administration to declassify information on the investigation of Paul Manafort, the former Trump campaign chairman who served federal prison time as a result of Robert Mueller’s investigation into the Trump campaign’s ties to Russia — and who’s now reportedly in talks to work with Trump again.

Trump, who pardoned Manafort in 2020, sparing him the remaining years of his sentence, is pulling for the GOP operative to get back into politics, according to the New York Times and Washington Post. Both reported last week that Manafort was in talks to help out with this year’s Republican National Convention in Milwaukee.

Manafort, 74, served prison time for tax and bank fraud convictions, the result of his hiding money he made through unregistered lobbying for pro-Russian Ukrainian politicians. He was released to home confinement due to coronavirus risks in 2020, shortly before Trump pardoned him in late 2020. Trump had praised Manafort for initially refusing to “break” and cooperate with investigators.

During the 2016 presidential campaign, Manafort also privately shared Trump campaign polling data with Konstantin Kilimnik, who investigators found had ties to Russian intelligence.

A bipartisan report from a Senate select committee investigating Russian interference in the 2016 election, published in 2020, found “that Manafort’s presence on the [2016] Campaign and proximity to Trump created opportunities for Russian intelligence services to exert influence over, and acquire confidential information on, the Trump Campaign.”

“Taken as a whole, Manafort’s high-level access and willingness to share information with individuals closely affiliated with the Russian intelligence services ... represented a grave counterintelligence threat,” the report said.

Wyden, in a letter to Director of National Intelligence Avril Haines, argued that extensive redactions in that report — related to Manafort’s interactions with Kilimnik, as well as evidence connecting Kilimnik to Russian intelligence’s hack-and-leak operations — ought to be made public. He also urged Haines to make public information on Oleg Deripaska, the pro-Russian Ukrainian oligarch to whom Manafort had previous ties.

When she was confirmed by the Senate in 2021, Haines pledged to undertake a review of the report and see what else might be declassified, Wyden noted. His letter urged Haines to finish that review “expeditiously,” if it is not already completed.

“It is critical that these details be made public to the greatest extent possible,” Wyden wrote. “As the Committee recommended, the public should be informed as soon as a foreign influence campaign is detected. In this case, a known ‘grave counterintelligence threat’ is reportedly joining a presidential campaign. Only by understanding the details of that threat can the public guard against a malign foreign influence effort that could once again threaten an American election.”