WASHINGTON — The special counsel’s office, citing new information from a cooperating witness, appeared on Wednesday to correct one element of its earlier allegations that Paul Manafort, President Trump’s former campaign chairman, lied about his contacts with a Russian business associate whom they have linked to Russian intelligence.
In a heavily redacted memo filed in United States District Court in Washington, prosecutors working for the special counsel, Robert S. Mueller III, cited new evidence that they obtained less than two weeks ago from Rick Gates, the Trump campaign’s deputy chairman.
They said their revised account should not change the recent ruling by Judge Amy Berman Jackson that Mr. Manafort had been untruthful about his interactions with the Russian associate, Konstantin V. Kilimnik, because they had presented sufficient other evidence of Mr. Manafort’s lies.
Nonetheless, the filing was a rare admission of a mistake by the special counsel’s office, which is winding up a nearly two-year investigation into Russian interference in the 2016 presidential race and whether anyone tied to the Trump campaign conspired in the effort to influence the outcome of the vote.
The filing could give new ammunition to Mr. Manafort’s defense team, which has argued that prosecutors overreached in accusing Mr. Manafort of lying because they were too eager to believe Mr. Gates. Lawyers for Mr. Manafort have repeatedly contended that Mr. Gates, who has been cooperating with Mr. Mueller’s team for the past year, is not a credible witness. Mr. Gates pleaded guilty to lying to federal investigators and conspiracy and is assisting the special counsel in hopes of a lighter sentence.
The subject in dispute was unclear from the filing, but one issue that prosecutors have said that Mr. Manafort lied about was whether he ordered Mr. Gates to give Trump campaign polling data to Mr. Kilimnik before the election. Court records suggest that prosecutors relied heavily on Mr. Gates for evidence of data transfers.
Mr. Manafort pleaded guilty last September to two conspiracy counts and, like a number of former Trump aides, agreed to cooperate with the special counsel’s investigation. But after a lengthy closed hearing on Feb. 13, Judge Jackson agreed with prosecutors that Mr. Manafort had breached his plea agreement by lying to them about three matters, including his relationship with Mr. Kilimnik.
That ruling could influence the severity of the punishment Mr. Manafort receives as a result of two prosecutions by the special counsel’s office. He is scheduled to be sentenced on March 7 by Judge T.S. Ellis III of United States District Court in Northern Virginia for eight counts involving financial fraud. Judge Jackson will sentence him for the two conspiracy crimes six days later. The combined sentences could mean that Mr. Manafort, 69, spends the rest of his life in prison.
Like other court filings discussing Mr. Manafort’s interactions with Mr. Kilimnik, the latest one, filed before Judge Jackson, was heavily redacted to protect active federal investigations. Even so, it makes clear that the prosecutors were trying to defend Mr. Gates’s credibility while at the same time correcting the record on which Judge Jackson relied in determining that Mr. Manafort had lied to them.
According to a footnote, news media coverage of the broken plea agreement led Mr. Gates’s lawyer to contact the special counsel’s office. Prosecutors followed up by interviewing Mr. Gates again on Feb. 15 and obtained new evidence, they said. But they said the new information does not “undermine the court’s conclusion as to the subject matter area as a whole.”