A Fort Providence, N.W.T., man has been handed the most severe sentence available under Canadian law.

A judge has declared Robert Walter Bonnetrouge a dangerous offender and sentenced him to remain in prison indefinitely.

In 2011, Bonnetrouge was convicted of sexual assault and confinement involving two teenage girls. They were the fifth and sixth victims of sexual assaults he has committed dating back to the time he was a teenager.

On Monday afternoon, Justice Louise Charbonneau rejected the idea of giving Bonnetrouge a fixed sentence with long-term supervision. She said that would mean he would be free of all supervision by the time he's in his early 50s.

Charbonneau said there would be no way to ensure that Bonnetrouge, who is in his mid-thirties, takes drugs to reduce his sex drive to manage his risk of harming others.

During his dangerous offender hearing, a psychiatrist said Bonnetrouge has a sexual preference for children, forced sex and suffers from an anti-social personality disorder.

The psychiatrist said he believes there will always be a high risk that Bonnetrouge will harm others.

The dangerous offender designation comes with an indefinite prison sentence.