Two Soviet-born businessmen with ties to Rudy Giuliani were arrested Wednesday on federal charges of violating campaign-finance laws through a six-figure donation they facilitated to President Donald Trump’s official super PAC.

Lev Parnas and Igor Fruman were taken into custody at Washington’s Dulles airport. U.S. Attorney Geoffrey Berman confirmed that the two were headed out of the country and that the timing of the arrest—before 6 pm on Wednesday—was prompted by fears of them escaping prosecution. Both men were about to board an international flight with one way tickets. Berman and local FBI Agent and charge William Sweeney made brief statements and left without taking questions. They said the case remained open and the investigation is ongoing.

Parnas and Fruman are charged with making illegal straw donations, including a $325,000 contribution to the group America First Action. As The Daily Beast first reported, that donation actually came from an entirely different, undisclosed company owned by Parnas. It is illegal to donate to federal political candidates in the name of another person or entity.

“They sell political influence not only to advance their own financial interests, but to advance the political interests of one foreign official, a Ukrainian government official who sought the dismissal of the U.S. ambassador to the Ukraine," said Berman.

Prosecutors allege a host of other, smaller straw donations designed, they say, to both evade federal campaign contribution limits and conceal the actual sources of the funds. Parnas is currently facing a civil lawsuit attempting to collect more than $500,000 that he owes a jilted business partner from a years-old movie deal gone bad.

In addition to the straw donations, prosecutors say that Parnas, Fruman, and their co-conspirators made donations using money provided by an unnamed foreign national, who was ineligible to contribute to federal political campaigns under U.S. law.

The Wall Street Journal first reported their arrests.

Parnas and Fruman are central to an ongoing impeachment inquiry against Trump. The two men assisted Giuliani, the president’s personal attorney, in his efforts to dig up dirt on Trump’s political opponents in Ukraine. Among the objectives they sought was the removal of the U.S. ambassador to Ukraine, whom Giuliani believed was standing in the way of investigations he and Trump wanted to see launched into Joe and Hunter Biden’s work in the country.

The campaign-finance allegations against them are inextricably linked with that effort. Prosecutors say their extensive political contributions, beginning in early 2018, were designed to curry favor with American policymakers in an effort to advance Parnas’ and Fruman’s political and business endeavors.

“I can’t comment at this point,” Giuliani told The Daily Beast. Parnas and Fruman are expected to appear in court Thursday, the Journal reported.

The charges Thursday are likely to have reverberations well beyond the president’s inner circle. America First Action has been a major player in congressional elections as well. And the indictment issued Thursday makes reference to one of those contests. The PAC spent more than $3 million to help elected former Rep. Pete Sessions (R-TX) after he wrote a letter calling for the ambassador’s firing. Sessions lost his 2018 election, but is running for a new seat in Congress this cycle.

America First told The Daily Beast this week that the money donated by Global Energy Producers was sequestered by the super PAC pending resolution of the legal issues surrounding it.