Rick Gates, the campaign aide, told an attorney for a us law firm that a Russian national they worked with in Ukraine was a former military intelligence officer, according to the filing late Tuesday in Washington federal court.
His reported knowledge of "Person A" came from Alexander van der Zwaan, the son-in-law of a Russian oligarch who was a lawyer at megafirm Skadden, Arps, Slate Meagher & Flom.
Both Mr. Manafort and Mr. Gates were indicted previous year for money laundering and other financial crimes committed while, the charges said, they tried to hide the money they received for their Ukraine work.
Had Trump-Russia believers read Mueller's memo more carefully, they might have noticed it specifically states that the conversations between "Person A", van der Zwaan and Gates "concerned potential criminal charges in Ukraine" about a report concerning the corruption trial of a former government official and the compensation Gates and Manafort were paid for their lobbying work, rather than anything pertaining to the Trump campaign or the U.S. presidential election.
Mueller's prosecutors have introduced evidence that Manafort emailed Kilimnik as recently as November 29, about changes to an editorial that ran in an English-language Ukrainian newspaper about his case.
Van der Zwaan is married to the daughter of German Khan, a director and co-owner of Alfa Bank.
The attorney who pleaded guilty in February to lying to Federal Bureau of Investigation agents about his contacts with former Trump campaign associate Rick Gates, asked prosecutors late Tuesday to let him skate with no jail time.
Prosecutors said he had a series of calls with Gates, Person A and a senior Skadden partner in September and October 2016, regarding "potential criminal charges in Ukraine about the Tymoshenko report and how the firm was compensated for its work", according to the filing.
What's particularly significant in the Mueller filing, though, are six words: "and had such ties in 2016".
Former Trump campaign manager Paul Manafort has been charged with money laundering over his work in Ukraine..
Mr. van der Zwaan originally told Mr. Mueller's investigators that he had not spoken to Mr. Gates since August 2016, but subsequently admitted he had lied after prosecutors confronted him with evidence of conversations.
It might not mean much - but if it didn't, why would van der Zwaan (and possibly Gates) try to keep it from investigators and risk an obstruction of justice charge?
Zwaan previously pleaded guilty to lying to investigators about his contacts with Gates during work for the pro-Russian government of Ukraine, which was ousted in 2014.
Within days, van der Zwaan chose to come clean.
He further alleged that "van der Zwaan admitted that he knew of that connection, stating that Gates told him Person A was a former Russian intelligence officer with the GRU".
Van der Zwaan, who was sacked by Skadden, is hoping that he can join his pregnant wife in Europe for the expected birth of their son in August, his lawyers said.