The U.S. Supreme Court on Monday rejected New Zealand-based internet mogul Kim Dotcom's challenge to the U.S. government's bid to seize assets held by him and others involved in the now-defunct streaming website Megaupload.

The justices left in place a lower court ruling that the U.S. government could seize up to $40 million in assets held outside the United States as part of a civil forfeiture action being pursued in parallel with criminal charges for alleged copyright violations and money laundering.

Dotcom and several other defendants have contested U.S. attempts to extradite them from New Zealand.