Former Trump campaign chairman Paul Manafort’s legal team filed a motion Tuesday to dismiss a second round of charges brought forth by Special Counsel Robert Mueller in Virginia.

The lawyers asserted that Mueller exceeded the scope of the investigation into Russian meddling and potential collusion with Trump campaign associates during the 2016 presidential election. And they claimed Mueller wasn't even investigating their client for any possible collusion.

Manafort lawyer Kevin Downing filed a motion in federal court to dismiss the “superseding indictment” brought by Mueller in early February, noting that “the charges against Mr. Manafort do not ‘arise directly from’ the special counsel’s investigation.”

“The conduct alleged here was not discovered because of the special counsel’s investigation into alleged coordination; nor was it ‘demonstrably related to’ that investigation,” the filing states, citing examples of alleged tax violations that occurred “well before the start of the Trump campaign or Mr. Manafort’s brief involvement with that campaign,” or the alleged failures to disclose foreign assets.

“The DOJ well knew about both of those supposed crimes because it had already investigated Mr. Manafort about them,” it said. “The special counsel thus cannot credibly claim that he discovered them because of his original investigation.”

Manafort’s attorneys added: “Indeed, the special counsel has never suggested that Mr. Manafort had anything to do with alleged 'coordination [with] the Russian government,' or even that he is investigating Mr. Manafort on that subject.”

A federal grand jury returned the new charges, which included conspiring against the United States, conspiring to launder money, failing to register as an agent of a foreign principal and providing false statements. That superseding indictment was brought against both Manafort and his ex-associate Rick Gates, separate from the original indictment in October 2017.

Manafort pleaded not guilty to the new round of charges, just as he he'd done to the first round in October, but Gates pleaded guilty to conspiracy to defraud the U.S. and lying to the FBI. Mueller’s team then moved to dismiss the superseding indictment against Gates.

Gates has intimate knowledge of Manafort’s years of political consulting work in Ukraine, as well as other events that sparked the interest of federal investigators.

Despite Gates’ guilty plea, Manafort has said that he will “continue to maintain my innocence,” and that he “hoped and expected” Gates would have had “the strength to continue the battle to prove our innocence.”

Earlier this month, U.S. District Judge T.S. Ellis III, who is assigned to the superseding indictment in Virginia, suggested that Manafort could face life in prison, and “poses a substantial flight risk” because of his “financial means and international connections to flee and remain at large.”

“Specifically given the nature of the charges against the defendant and the apparent weight of the evidence against him, defendant faces the very real possibility of spending the rest of his life in prison,” Ellis wrote.

Fox News' Kelly Phares contributed to this report.