Lawyers for one of three Afghan military officers facing deportation after sneaking away from a military training exercise at Joint Base Cape Cod say he was improperly denied entry into Canada when he arrived at the border seeking refugee status.

Supporters say Capt. Mohammad Askarzada should have been exempt from a 10-year-old treaty under which he and the other officers apparently were turned away.

The 2004 Safe Third Country Agreement requires people seeking asylum at Canada-U.S. land border crossings to apply in whichever country they arrive in first, with some exceptions.

Canadian attorney Razmeen Joya says Askarzada met one of the exceptions, by having an uncle in Canada. She has submitted documents and requested that Canadian authorities reconsider.

A spokeswoman says the Canada Border Services Agency doesn't comment on cases.