Special Counsel Robert Mueller was given permission by the Justice Department to investigate allegations that former Trump campaign manager Paul Manafort colluded with the Russian government.
According to a memo filed in court Monday, Deputy Attorney General Rod Rosenstein gave Mueller that authorization last August. Rosenstein has been overseeing Mueller's investigation since Attorney General Jeff Sessions' recused himself.
Monday's court filing is part of a case involving Manafort — who's asked a D.C. judge to throw out some of the criminal charges against him.
Manafort's lawyer argued Mueller shouldn't be able to indict Manafort for what he did before joining the Trump campaign in 2016.
Mueller's team is trying to prove they do have the authority to investigate alleged crimes Manafort committed, even his ties to Ukraine — with the Justice Department's approval.
Manafort hasn't been charged with anything relating to Russian interference or the 2016 presidential election. He's scheduled to appear before a jury in Virginia in July, and then his Washington, D.C. trial will begin in September.
Additional reporting from Newsy affiliate CNN.