The alleged incident occurred just before Christmas as Williams headed to the Baltic country as part of a celebrity tour to boost soldiers' morale.

The victim was another passenger on the flight, but has not been identified.

The Canadian Forces National Investigation Service, which has jurisdiction on military aircraft, charged Williams with one count of sexual assault and one count of assault under Canada's Criminal Code.

It said in a statement the case would be handed over to civilian prosecutors in Ottawa for consideration.

Canada deployed 450 soldiers to Latvia as part of a NATO military build-up on its eastern flank in response to Russia's annexation of Crimea.

Williams, who played in the NHL from 1974 to 1988, has been a regular on morale tours, travelling to Afghanistan and other hotspots on 14 occasions to play ball hockey with the troops.

The charges against the 64-year-old come at a time when the military has been cracking down on sexual misconduct in its ranks.