Ontario's premier is calling for the federal government to help keep Canada from becoming a "dumping ground" for offenders after a U.S. judge allowed a man to be sent to this country as punishment.

After American citizen Malcolm Watson, a former teacher, was convicted of having sex with a 15-year-old student, a New York state judge gave him the choice between serving three years of probation in Canada or time behind bars.

Malcolm Watson agreed to a three-year sentence at his home in Canada.
(CBC)

Watson, 35, agreed to serve the sentence in St. Catharines, Ont., where he lives with his Canadian wife and three children.

Premier Dalton McGuinty wants Ottawa to work with the province to fight the controversial decision that has immigration officials divided on its legality.

"I hope that we are of one mind in this regard so that we don't become some kind of a dumping ground for convicted offenders," McGuinty told CBC on Tuesday.

"It's obviously not the kind of precedent that we want to allow the Americans to establish, and it's not the kind of thing we're prepared to accept," he added.

Canada's plans unclear

Canada's Immigration Minister Monte Solberg has not stated what action, if any, the federal government plans to take.

"If anyone who is a non-citizen is living in Canada who we perceive to be a threat to the public, we're going to remove them as quickly as we can," said Solberg.

However, U.S. authorities say Watson, who has no prior convictions, is not likely a threat.

The relationship between the teacher and 15-year-old student was reportedly consensual.

If the Canadian government decides to take action, it could simply bar him from going back to Canada after a probation hearing.

The former teacher is forbidden from re-entering the U.S. except for probation hearings.

However, a final decision may hinge on the different consent laws in Canada and the U.S., and whether Watson would have been charged with the offence in Canada.

In Canada, the age of consent is 14 years, unless sex occurs during a relationship of trust or dependency, such as a teacher-student relationship, in which case the age of consent rises to 18.

In New York state, the age of consent for male-female sexual relations is 17.