For more than seven years, the U.S. Depart­ment of Justice has fought to control $250 million the government claims is dirty money rooted in the criminal exploits of a former Ukrainian prime minister.

Federal prosecutors in Washington who specialize in asset forfeiture contend that Pavlo Lazarenko’s money laundering proceeds are scattered in bank accounts in Antigua and Barbuda, Switzerland, Liechtenstein, Lithuania and the British island Guernsey, and that the United States is entitled to seize those overseas funds.