Two helicopters carrying French sports stars filming a popular European reality show have crashed in a remote part of Argentina, killing 10 people, including two Olympic medal winners and a sailing champion.

The helicopters apparently collided in mid-air near Villa Castelli in La Rioja province, about 730 miles north-west of Buenos Aires. All 10 people on board - eight French nationals and two Argentine pilots - were killed.

Among the dead were French Olympic gold medal swimmer Camille Muffat, Olympic boxer Alexis Vastine and sailor Florence Arthaud, according to a statement from La Rioja's government.

The news of the deaths during the filming of the reality survival show Dropped sent the French sports world into mourning.

French president Francois Hollande said: "The brutal demise of our compatriots is an immense sadness."

Muffat, 25, won the gold medal in the 400-metre freestyle at the Olympic Games in 2012, adding a silver medal in the 200-metre freestyle and a bronze in the 4 by 200-metre freestyle relay. She had since retired from swimming to focus on her personal life.

Olympic gold medallist and swimmer Amaury Leveaux said: "French sport has lost a great champion."

Alexis Vastine won a bronze medal at the 2008 Games in Beijing, but his semi-final loss to Manuel Felix Diaz was marred in controversy as he was docked points by the referee in the final round.

French secretary of state for sport Thierry Braillard said: "I'm profoundly saddened. French sport has lost three stars this morning."

Former France and Arsenal striker Sylvain Wiltord, ice skating champion Philippe Candeloro and former Olympic swimming champion Alain Bernard and veteran cyclist Jeannie Longo are among the other French athletes taking part in the show, but none were involved in the accident.

Wiltord tweeted: "I am sad for my friends, I'm trembling, I'm horrified, I don't have words. I can't say anything."

Arthaud, who was 57, was a pioneer in sailing. In 1990, she won the famed Route du Rhum race - a transatlantic single-handed yacht race between Brittany and the Caribbean islands of Guadeloupe - on her boat Pierre 1er.

The crew had arrived on Sunday in Villa Castelli, where it had previously filmed a version of Dropped show for Switzerland and Denmark.

The crash happened in a rugged, sparsely populated area is on the edge of the Andes mountain range that separates Argentina and Chile. The crash happened around 5.15pm local time.

Adventure Line Productions, the show's producers, said its teams are "devastated and share the deep pain of the families and loved ones".

IOC president Thomas Bach said the Olympic world was in mourning.

"We are shocked by this sad news," he added. "Our thoughts are with the families and friends of these great athletes who have left us."

He said "the world of sport and the Olympic family have lost three of their key members", who "were all not only champions in their sport but also contributed greatly as role models".

The Olympic flag will be flown at half-mast for three days at the International Olympic Committee's headquarters in Switzerland.