Kilimnik faces two counts of obstruction of justice, The Washington Examiner reported.
Kilimnik served as Manafort's aide when the latter would do business in the Ukraine and Russia, The Atlantic reported. Kilimnik was Soviet-born and could translate between English and Russian speakers. Manafort described the man as "my Russian brain" and would allow him to sit through his meetings with the area's politicians and oligarchs, The Atlantic reported.
By 2011, Kilimnik was the main point of contact between Manafort and his only clients, a group of what The Atlantic called, "former gangsters" that ruled Ukraine under the banner, "the Party of Regions."
During the same time he was working for Manafort, there were rumors that Kilimnik was also working for Russian intelligence, The Atlantic reported.
Kilimnik was rumored to be "Person A" in two filings of Mueller's against Manafort. "Person A" was connected to Russian intelligence through the 2016 presidential election, The Atlantic reported.
Kilimnik is a Russian citizen from Moscow, CNBC reported.
Manafort was already indicted on five other charges: conspiracy against the United States, conspiracy to launder money, unregistered agent of a foreign principal, false and misleading FARA statements and false statements, The Washington Examiner reported.
Manafort is facing criminal charges in two different jurisdictions: One in federal court in Virginia, and another in federal court in Washington, D.C., CNBC reported.