Swiss snowboard champion Estelle Balet has been killed in an avalanche, police have said.

Balet had won her second Freeride World Tour title in Verbier just a few weeks ago.

The 21-year-old was hit by the avalanche early on Tuesday morning while filming a movie on the Portalet mountain in Orsieres, close to Switzerland's southern border with France and Italy.

Balet, who was wearing safety equipment, had followed another snowboarder - who was not caught up in the avalanche - down the slope.

Rescuers were able to free Balet, according to Valais State Police, but she died at the scene. An investigation has been launched into the cause of the accident.