New York prosecutors say two Trump donors have been charged with violations of campaign finance laws.
The charges say Soviet-born businessmen Lev Parnas and Igor Fruman conspired to funnel foreign money to candidates for federal and state office.
The pair have been associated with US President Donald Trump's personal lawyer Rudy Giuliani.
They have been peddling unsubstantiated corruption claims against a top Democratic presidential contender.
Both men are US citizens. Mr. Parnas was born in Ukraine, Mr. Fruman in Belarus.
They are expected to appear in federal court in Virginia Thursday.
US media report the two men were arrested at Dulles International Airport in Virginia before they could board a scheduled flight to Vienna, Austria, Wednesday night.