The U.S. has filed a civil forfeiture complaint against $61 million in cryptocurrency that it alleges proceeds from black-market sales of sanctioned Iranian crude oil and petroleum products.

The complaint, brought by the U.S. Attorney’s Office for the Southern District of New York, alleged Tehran used a network of cryptocurrency actors in China and elsewhere to launder more than $1.5 billion in illicit oil money intended to benefit the Iranian military and the Islamic Revolutionary Guard Corps. These proceeds were intended to finance the Iranian government and military components.

“Today we are seizing and seeking to forfeit more than $61 million of…