10/03/2015 04:15 GMT | Updated 10/03/2015 13:59 GMT

Dropped Helicopter Crash Kills 10 Including London 2012 Olympians Camille Muffat And Alexis Vastine

Two helicopters carrying French sports stars filming a survival reality show crashed into each other in a remote part of Argentina, killing 10 people, including two London 2012 Olympic medal winners and a sailing champion, authorities said.

French stars Camille Muffat, an Olympic gold medalist swimmer, sailing champion Florence Arthaud and Olympic boxer Alexis Vastine were among those killed in the freak accident when they were filming the European reality programme "Dropped".

The helicopters apparently collided in midair on Monday, above rugged land in La Rioja province, 730 miles northwest of Buenos Aires, La Rioja Secretary of Security Cesar Angulo told TN television.

All 10 people on board - eight French nationals and two Argentine pilots - were killed.

Two London 2012 medal-winners were killed

"An explosion occurred and it's believed that they collided," said Angulo, referring to the helicopters. Photographs showed the burning and smoking wreckage of the helicopters on the ground in dry scrubland with people gathered nearby.

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

The show's producers, Adventure Line Productions - or ADL - released a statement confirming the 10 deaths.

A photo of the athletes participating in Dropped from the Facebook page of Philippe Candeloro, the ice skating champion, who wasn't in the crash

"All the ADL teams are devastated and share the deep pain of the families and loved ones they are in contact with," the statement said. "We are in contact with the production teams on site (and) with the French and Argentine authorities. We will give more information as soon as possible."

Argentine authorities were at the scene of the crash late Monday trying to determine its cause.

The crash scene in the rugged terrain

The news of the deaths plunged the French sports world into mourning.

"The brutal demise of our compatriots is an immense sadness," said French President Francois Hollande in a statement.

French Secretary of State for Sport Thierry Braillard said on the BFM TV channel, "Some had finished their careers and one was dreaming of gold in Rio. I'm profoundly saddened. French sport has lost three stars this morning."

Photo gallery Candidates Of Reality Show 'Dropped' See Gallery

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

"Camille was quite a shy and reserved person. She was discreet. But when it was time for a bit of a laugh she was always there," said Olympic gold medalist Amaury Leveaux. "French sport has lost a great champion."

French athlete Camille Muffat won gold in the women's 400-metre freestyle swimming at London 2012

Richard Papazian, the president of the Nice swimming club in southern France where Muffat used to swim, could barely contain his emotion.

"I could not believe it and then the news was confirmed. What a terrible tragedy," said Papazian on BFM television, his voice cracking. "I had a lot of affection for Camille. I can't find the words. It's a terrible destiny."

Vastine won a bronze medal at the 2008 Games in Beijing, but his semifinal loss to Manuel Felix Diaz was marred in controversy as he was docked points by the referee in the final round. Vastine broke down in tears after the defeat.

In 2012, he lost in the quarterfinals at the London Games also amid controversy when he drew on points against Taras Shelestyuk of Ukraine but lost on the countback rule, thus missing out on a medal.

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

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

Candeloro, in a statement on his Facebook page, said he is "extremely shocked" but "safe and sound. "

The TV show was a survival-style reality programme

Other French athletes spoke of their sorrow over the loss.

"I don't have words to express the pain I feel, the tears are flowing and won't stop," former French sprinter Muriel Hurtis - a gold medalist in the 4 x 100 relay at the 2003 world championships.

The Argentine statement identified the remaining victims as Laurent Sbasnik, Lucie Mei-Dalby, Volodia Guinard, Brice Guilbert and Edouard Gilles, as well as Argentine pilots Juan Carlos Castillo and Roberto Abate.

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

La Rioja Secretary of Security Angulo said one of the helicopters belonged to La Rioja province and the other belonged to neighboring Santiago del Estero province.

"The helicopter from La Rioja was a Eurocopter with a capacity to hold six people. It appears to have brushed against the other helicopter from Santiago del Estero shortly after takeoff," the statement from the provincial government said.

The crash occurred around 5:15 p.m. local time, according to the Argentine news agency Telam. The rugged, sparsely populated area is on the edge of the Andes mountain range that separates Argentina and Chile.

Photo gallery Dropped Reality Show Disaster See Gallery