Rebecca Adlington and Amir Khan are among those to have paid tributes after three French sports stars died in a helicopter crash in Argentina.

Two helicopters collided near Villa Castelli in La Rioja province, around 1200 kilometres north-west of Buenos Aires, killing eight French nationals and two Argentinians during filming for reality television show 'Dropped'.

Among those killed were Olympic swimming champion Camille Muffat, boxer Alexis Vastine and sailor Florence Arthaud, the Argentinian government said.

Twenty-eight-year-old Vastine claimed light welterweight bronze at the 2008 Olympics in Beijing, while 57-year-old Arthaud was considered one of the world's best sailors.

Khan, who secured a lightweight silver medal for GB at the 2004 Olympics before going on to become a pro world champion, said: "I'm very sad to hear of the passing of Alexis Vastine.

"I had the pleasure of competing against him in the amateurs and would like to send my deepest condolences to all his family and friends during this difficult time."

British Olympic boxing champion Nicola Adams sent her condolences on Twitter, saying: "R.I.P Camille Muffat, Alexis Vastine and Florence Arthaud. My heart goes out to there family and friends."

The British Amateur Boxing Association expressed its sadness at the tragedy in a statement, describing Vastine as "a top-class boxer and a fine sportsman", while the International Boxing Association said: "A remarkable athlete, and a tremendous asset to the world of boxing, Vastine will be sorely missed by all involved in the sport and beyond."

Bradley Saunders, who beat Vastine at 2007 World Championships but lost to him at the 2008 Olympics, said: "I sparred with Alexis all round the world and I considered him a friend even though we were also rivals.

"I under-estimated him at the Olympics because I'd beaten him so easily at the worlds, but he'd done his homework and he beat me.

"He was a really nice guy with a nice family and hearing this kind of news is unbearable."

Muffat won gold in the 400 metres freestyle at London 2012 - ahead of bronze-medallist Adlington - as well as silver in the 200m freestyle and bronze in the 4x200m freestyle relay.

Great Britain's two-time Olympic champion Adlington wrote on Twitter of the 25-year-old on Tuesday: ''So sad and shocked to wake up to hear the tragic death of Camille Muffat. She was an amazing sportswoman, competitor and lovely person.

''My thoughts go out to not only all her friends and family but to all the family and friends of all the 10 victims. Its an extremely sad day.

''RIP Olympic Champion Camille Muffat. You will be dearly missed. X''

Meanwhile, French sailor Francis Joyon - who broke the record for a solo crossing of the Atlantic, a feat previously achieved by Arthaud - tweeted: "Deeply saddened by this tragedy.

"I've always had great admiration for Florence and my thoughts are with her family and relatives."

French president Francois Hollande said in a statement published on the website of French daily Liberation: ''The brutal demise of our compatriots is an immense sadness.''

Former Arsenal forward Sylvain Wiltord, a reported contestant on the reality show who was not in either helicopter, tweeted: ''I am sad for my friends, I tremble, I am horrified, I have no words, I cannot say anything.''

Tributes poured in on Tuesday from around the world of sport as the news became known.

Formula One racing driver Romain Grosjean tweeted: ''Horrified to learn of the death of Florence Arthaud, Camille Muffat, Alexis Vastine and all the other people who were on board.''

Tennis player Paul-Henri Mathieu posted: ''Terrible ... Courage to families and friends.''

Adlington's fellow British swimmers Fran Halsall, Jazz Carlin and Hannah Miley paid their respects to Muffat on Twitter.

Halsall said: ''Shocked and saddened to hear about the death of Camille Muffat, taken far too young such a lovely person and inspirational athlete #RIPCM.''

British Swimming head coach Bill Furniss, who previously coached Adlington, said in a statement: "Camille was someone who commanded respect as both a great competitor and as a person.

"Rebecca and her had some tremendous battles over the years and she will be sadly missed.

"I would like to offer my condolences to her family, friends and all at French Swimming."

French Swimming Federation president Francis Luyce, quoted by L'Equipe, said: "I am horrified, it is beyond comprehension.

"The swimming family has lost one of its most loved ones, one of its greatest swimmers. I keep a picture of a radiant Camille - she was happy and deserved to be. Rarely in my life have I been as troubled as today."

Swiss sailor Laurent Bourgnon, winner of the Route du Rhum in 1994 and 1998 and third in 1990 when Arthaud claimed victory, said of her in a tribute quoted by L'Equipe: "It has always struck me with Florence that there was this big gap, like a split personality, between her life on land and when she found herself at sea in command of a ship.

"On board, she had an extraordinary force that you would not have given her when she was seen on the ground.

"At sea, she had a power, an energy, a joie de vivre, with a highly developed marine sense and huge marine capabilities."

In its tribute to Arthaud, the International Sailing Federation said: "ISAF expresses its sincere condolence to Arthaud's family and friends in the sailing world and all those affected."

L'Equipe also quoted UEFA president Michel Platini saying: "I want to express my deepest condolences to the families and friends of these three huge French sports stars that were Florence Arthaud, Camille Muffat and Alexis Vastine.

"Like millions of French, I admired them. My thoughts are with them on this black day of French sport, and also with the families and friends of the seven other victims of this tragic and terrible accident. "