BANGOR, Maine — A retired Royal Canadian Mounted Police officer accused of smuggling narwhal tusks across the border pleaded guilty Wednesday in U.S. District Court to 10 money-laundering counts.

Gregory Logan, 59, of St. John, New Brunswick, smuggled 250 tusks valued at $1.5 million to $3 million into Maine in false compartments in his vehicle, prosecutors said.

Narwhals are medium-sized whales known for spiral tusks that can grow longer than 8 feet. They are protected by the U.S. and Canada.

Logan, who was a Canadian Mountie when he began bringing the tusks into the U.S., faces up to 20 years in prison and a $500,000 fine for each count.

No sentencing date has been set.

Logan was originally charged with smuggling, conspiracy and money laundering. He pleaded guilty in Canada to a related wildlife smuggling crime, and terms of his extradition limited U.S. charges to money laundering.

Prosecutors say Logan kept a post office box at a shipping store in Ellsworth, where the tusks were shipped to U.S. buyers, and maintained a bank account in Bangor to aid in funneling money back to Canada.

Logan was originally charged along with two U.S. residents.

Andrew Zarauskas, of Union, New Jersey, was convicted and sentenced to 33 months. Charges against Jay Conrad, of Lakeland, Tennessee, were dismissed.

Logan, who retired from the Royal Canadian Mounted Police in 2003, served four months of home detention and paid a $350,000 fine in Canada.