It says those business interests date to as early as 2005 and have "no connection whatsoever" with the 2016 campaign. The suit also argues that the investigation of Manafort is "completely unmoored from the special counsel's original jurisdiction."
Mueller's office declined to comment.
A spokeswoman for the Justice Department said: "The lawsuit is frivolous but the defendant is entitled to file whatever he wants."
Manafort has filed suit as the politics surrounding the investigation are heating up. Many House Republicans say that the special counsel's probe is tainted by political bias and that it will never give Trump a fair shake. Some of the president's surrogates have called for Mueller's investigation to be shut down and for the Justice Department to appoint another special counsel to investigate former Democratic presidential candidate Hillary Clinton.
The president has repeatedly called the investigation a "witch hunt," but he also recently told the New York Times that he thinks Mueller is "going to be fair." Trump also said — again — that "there's been no collusion."
Deputy Attorney General Rod Rosenstein also was named as a defendant in the Manafort civil suit. Rosenstein appointed Mueller in May after Trump fired FBI Director James Comey. Rosenstein supervises Mueller's investigation in lieu of Attorney General Jeff Sessions, who recused himself from Russia-related matters because of his role in the Trump campaign.
Rosenstein's order appointing Mueller empowers the special counsel to investigate "any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump." But it also authorizes Mueller to probe "any matters that arose or may arise directly from the investigation."