Swiss police say snowboarder Estelle Balet has been killed in an avalanche.

Police say the 21-year-old Swiss athlete was struck by the snow slide early Tuesday morning while filming above Orsieres, near Switzerland's southern border with France and Italy.

She had been following another snowboarder, who wasn't caught in the avalanche.

Valais state police said in a statement that rescuers were able to free Balet, who had been wearing special safety equipment, but she died at the scene.

Balet recently won the Freeride World Tour. She was a member of watchmaker Swatch's professional team.

Police say they have launched an investigation into the cause of the incident.