Balet, who earlier this month won her second world freeride title in the Swiss resort of Verbier, was killed on Tuesday morning near Orsières in her home canton of Valais, police said.
The 21-year-old champion was making a film on the Portalet mountain when the avalanche hit just after 8am on Tuesday morning.
By the time rescue workers arrived by helicopter at the scene, the snowboarder had been dug free, however resuscitation attempts failed to revive her and she died at the scene.
According to police another person had already skied the slope before Balet descended. As she did, a wave of snow of around one kilometre in length detached from the mountain and swept her away.
Balet was wearing a tracking device, an airbag and a helmet.
“I feel a huge sadness, a feeling of bitterness and above all solidarity with her family and friends,” Nicolas Hale-Woods, founder of the Freeride World Tour, told AFP.
“It is a reminder that no matter how well prepared you are, taking part in freeride in the mountains has an element of uncertainty,” he added.
A tribute added to her profile page on the Freeride World Tour website said: “Estelle Balet was a naturally gifted shining star and demonstrated remarkable talent as she quickly became a household name on the Freeride World Tour, bringing home her second title as World Champion just a few weeks ago in Verbier.”
Balet was swept away by an avalanche in the Orsieres area of the Valais. Photo: Valais police
Speaking to Swiss media, the snowboarder’s father Eric Balet called his daughter “a real ray of sunshine. She lived her life with passion, it’s all gone so quickly.”
Alain Perruchoud, the president of the commune of Chalais where Balet lived, told the paper: “Everyone here knew Estelle.”
“I can hardly imagine the pain of losing a child in these circumstances.”
Tributes also poured in on social media, with British ski star Chemmy Alcott calling Balet “a lovely, friendly girl”.
Christian Constantin, president of FC Sion, tweeted “Her smile, her love of life, her bravery and her audacity will be missed.”
— Freeride World Tour (@FreerideWTour) April 19, 2016
Balet came from the Valais region of Switzerland and had been snowboarding since the age of 10. She had been on the Freeride World Tour since the junior level.