On Friday, a 400-meter wide avalanche starting at an altitude of about 2,200 meters above the sea hit the Swiss ski resort in the Vallon d'Arbi region near to Riddes in canton Vaud.
According to the Swissinfo.ch news portal, the identity of the deceased person has not yet been established.
Valais cantonal police reportedly said that those missing were two French nationals and one Swiss.
According to a police representative, there are little chances of fnding them alive.
Switzerland has experienced exceptionally high levels of snow this winter, which has raised avalanche warnings to the maximum alert in several areas.