Donald Trump’s one-time presidential campaign chairman Paul Manafort admitted in a court filing on Tuesday that he provided polling data from the campaign to a Russian with ties to intelligence during the 2016 US presidential race.

Manafort denied allegations from the Russian collusion investigation of Special Counsel Robert Mueller that he had lied about his dealings with Konstantin Kilimnik, arguing he merely forgot details during the hectic election campaign.

The specifics of the Mueller allegations were not previously known publicly, having been blacked out in a heavily redacted December 7 filing by the Russia collusion prosecutor’s team.But in Manafort’s response, the electronic formatting for the redaction could easily be bypassed, revealing exactly what Manafort was accused of lying about.

Manafort, 69, has already been convicted in one case brought by Mueller, and pleaded guilty in another, over financial crimes related to his work in Ukraine before the 2016 campaign, and for witness tampering, which also involved Kilimnik.

“The same is true with regard to the government’s allegation that Mr. Manafort lied about sharing polling data with Mr. Kilimnik related to the 2016 presidential campaign,” they added in the redacted section.

The previously unknown allegation adds to mounting evidence that contacts between Russians and the Trump campaign were more than just incidental, though Mueller has yet to make a case that there was any conspiracy that involved the campaign.

He had a deal to cooperate with Mueller while delaying sentencing, which eventually could mean years in jail. But in December Mueller’s team asked the court to schedule sentencing, saying Manafort had violated that deal by lying to investigators. Manafort’s lawyers said their client had no reason to misrepresent the truth in his 12 interviews with investigators late last year.