Two American men face charges for allegedly smuggling prized narwhal tusks from Canada to the U.S., officials said.

Andrew Zarauskas, of Union, N.J., and Jay Conrad, of Lakeland, Tenn., have both been arrested and face conspiracy, money laundering, and smuggling charges, the U.S. justice department said in a statement last month.

Documents allege from 2007 to 2010 the men transported the narwhal tusks illegally across the U.S. border and sold them.

If convicted, Conrad and Zarauskas face up to twenty years in prison and fines of up to $250,000, the justice department said.

U.S. federal law prohibits the sale of marine mammal parts and the narwhal is protected there under the Marine Mammal Protection Act. The narwhal is listed as a "species of concern" in Canada and is being considered for listing under the federal Species at Risk Act, according to Fisheries and Oceans Canada.

Narwhal, also known as sea unicorns, live in the Arctic and are hunted by the Inuit for meat and ivory. The males are sought after as they have spiralled tusks that can grow to around 2.5 metres long.