BANGOR — One of two Americans and a Canadian charged in a cross-border case of smuggling rare narwhal tusks into the U.S. from Canada is scheduled to plead guilty Tuesday in U.S. District Court to charges connected with the operation.

Jay Gus Conrad, 67, of Lakeland, Tenn., is expected to plead guilty to some or all of the charges on which he, Andrew J. Zarauskas, 60, of Union, N.J., and Gregory Robert Logan, 56, of Woodmans Point, New Brunswick, Canada, and Grande Prairie, Alberta, Canada, were indicted by a federal grand jury in December 2012 .

All three are charged with multiple counts of conspiracy to import merchandise, conspiracy to launder money, smuggling goods into the U.S. and money laundering.

The male narwhal whale’s ivory tusk spirals counter-clockwise from its head and can be as long as eight feet, according to NationalGeographic.com. Scientists have speculated it is prominent in mating rituals, perhaps used to impress females or to battle rival suitors.

The narwhal is a medium-sized whale native to Arctic waters and protected in the U.S. by the Marine Mammal Protection Act. In Canada, it is protected in the Convention in International Trade in Endangered Species of Wild Fauna and Flora. Only the Inuits may legally harvest the whale in Canada. The Inuits may legally sell the tusks in Canada.

Logan purchased the tusks from retail outlets in northern Canada, then marketed them on the Internet, according to the indictment filed in federal court in Bangor. He hid them in special compartments in his truck and a small trailer, then brought them into Maine at the Milltown Port of Entry in Calais.

After crossing the border, Logan allegedly drove to the Bangor FedEx location and sent more than 75 shipments of the tusks to customers, including Conrad and Zarauskas, between December 2000 and February 2010. Logan and an unnamed co-defendant set up a bank account in Bangor and a mailing address in Ellsworth, where payments from Conrad for the illegal tusks were sent, the indictment said. Logan then allegedly had the money transferred to a Canadian bank or withdrew it in large amounts from the Bangor bank.

Last month, Logan, a former Canadian Mountie, was arrested in St. John, New Brunswick, on the U.S. charges that stemmed from the decadelong operation. He is being held without bail while awaiting extradition to the U.S., according to news reports published in Canada.

Information about when Logan will be in court in Bangor was not available Sunday on the federal court’s electronic case filing system.

Logan was convicted in October in a Canadian court on seven counts of trafficking offenses that involved 250 narwhal whale tusks, according to the Canadian Broadcasting Co. He was given an eight-month conditional sentence that included four months of house arrest. A conditional sentence in Canada similar to a suspended sentence in Maine courts.

Charges in Canada against Logan’s wife, Nina Lorene Logan, 52, were dismissed. A fourth individual, whose name has not been released, was indicted in federal court in Bangor with Logan, Conrad and Zarauskas.

The ex-Mountie also was ordered to pay a $385,000 fine — the highest ever issued in Canada for violating that country’s wildlife laws, according to Canadian news reports. Logan also was prohibited from possessing or purchasing marine mammal products for a period of 10 years.

Logan originally was arrested by Environment Canada in 2011 after a 2½-year investigation dubbed Operation Longtooth that was sparked in 2009 on a tip for U.S. authorities, the National Post reported.

Conrad, and the others, if convicted, each face up to 20 years in federal prison. Each also could be fined $500,000 or twice the value of the money involved in the offense, whichever is greater.