Two of Rudy Giulianis associates were arrested Wednesday for campaign finance violations related  to President Donald Trump‘s attempts to investigate Joe Biden with help from Ukraine’s government.

A spokesman for the Southern District of New York said Lev Parnas and Igor Fruman were arrested  at Dulles Airport near Washington, D.C. The pair of Soviet-born businessmen — who are now American citizens based in Florida — are scheduled to appear in court Thursday in Virginia. Parnas helped Giuliani build connections with Ukrainian prosecutors. Giuliani’s two associates also reportedly donated hundreds of thousands of dollars to a Trump-allied Super PAC.

Giuliani attempted to play down the severity of a campaign finance investigation into his two associates in an interview with the Times last month.

“They had a campaign finance issue,” said Giuliani in September. “I referred them to a campaign finance expert who pretty much resolved it.”

Giuliani also refused to immediately comment on his associates’ arrest on Wednesday, per BuzzFeed News’ Miriam Elder: 

Last week, House Democratic committee leaders subpoenaed Giuliani, Fruman and Parnas for documents related to Trump’s efforts to solicit help from Ukraine to get dirt on his opponent in the 2020 election. Giuliani has repeatedly said he refuses to cooperate with Democratic lawmakers’ efforts to investigate Trump’s contacts with foreign governments and even said he believes the president is being “framed.”

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The Wall Street Journal reported that two other individuals, Ukrainian-born American Andrey Kukushkin and American-born David Correia, were also indicted this week after being charged with conspiracy.