A U.S. court on Monday unsealed campaign finance violation charges against Russian businessman Andrey Muraviev as part of a case implicating two associates of Rudy Giuliani, ex-U.S. President Donald Trump's former personal lawyer.

Federal prosecutors in Manhattan say Muraviev contributed to U.S. political candidates with the help of Lev Parnas and Igor Fruman, the Giuliani associates. Foreign nationals are barred from donating funds to U.S. election campaigns. Muraviev is charged with two counts of violating campaign finance law.

The Sept. 17, 2020 indictment had previously been kept under seal. The unsealing comes as Washington seeks to target wealthy Russian businessmen with possible sanctions, asset seizures and criminal charges in a bid to pressure President Vladimir Putin to stop his invasion of Ukraine.

Muraviev, who is based in Moscow, could not be reached for comment.

Parnas was convicted of six counts of campaign finance violations in October. Prosecutors said Parnas used $100,000 from Muraviev to donate to candidates who could help him and Fruman obtain licenses to operate legal cannabis companies in the United States.

"(Muraviev) attempted to corrupt our political system to advance his business interests," Damian Williams, the U.S. Attorney for the Southern District of New York, said on Monday, adding that his office would continue "rooting out efforts by foreigners to interfere with our elections."

Fruman had earlier pleaded guilty to one count of soliciting money from a foreign national for a U.S. political campaign.

Parnas and Fruman, who were born in Ukraine and Belarus, respectively, are best known for helping Giuliani investigate Joe Biden ahead of the 2020 U.S. presidential election.

Giuliani, also a former New York City mayor, has not been charged with any crimes and has denied wrongdoing.

Andrey Kukushkin, a Ukraine-born California businessman who worked with Muraviev, was convicted of campaign violations alongside Fruman last year. His lawyer on Monday said he was hoping to help the Ukraine war relief effort in lieu of serving prison time.