France's state secretary of sport Thierry Braillard has confirmed that an investigation has been opened following a helicopter crash in Argentina that killed 10 people, including three sports stars.

Camille Muffat, an Olympic gold medallist swimmer, boxer Alexis Vastine and sailor Florence Arthaud lost their lives when two helicopters collided in La Rioja provence during the filming of reality television show Dropped.

Braillard said: "French sport lost three stars. So we are all deeply wounded because we all knew, met, or saw Florence Arthaud, Camille Muffat or Alexis Vastine. So the French sport today is really sad.

"The foreign minister opened this morning a crisis unit, the prosecutor opened an investigation, as is always done when a French citizen dies abroad. The French ambassador in Argentina and his people are on their way to the location.

"Argentina also opened an investigation. Right now, we have to be very careful, but we know that the accident happened at 5:30pm.

"Unquestionably, the two helicopters collided with each other during the take-off, and the fact that they collided put them on the ground with an explosion, and so the people inside died instantly.

"It's all I can say right now. But the president was informed immediately this morning, as well as the first minister, and tomorrow at 1.00pm, with Patrick Kanner, minister of the city, the youth and sports, we'll have a ceremony for our eight fellow countrymen, including three high-level sportsmen."

A statement from Zodiak Media, the production company behind Dropped, added: "Across the entire Zodiak Media group we are incredibly saddened by this tragedy and our thoughts are with everyone involved and their families at this time following the terrible helicopter crash on the ALP production of Dropped in Argentina.

"The information we have to date is that the accident occurred during transportation by helicopter carrying members of cast and crew to the shooting location. A few minutes after take-off, around 5pm on Monday, while the two helicopters were flying in parallel lines, one of them unexpectedly deviated from its course and collided with the other.  

"The first helicopter was filming the second one which was transporting the cast. Amongst the victims, were the three sporting personalities [Florence Arthaud, Camille Muffat and Alexis Vastine], five technical crew members who have been collaborating with us on many productions [Laurent Sbasnik, Lucie Mei-Dalby, Volodia Guinard, Brice Guilbert and Edouard Gilles] and two highly experienced pilots [Juan Carlos Castillo and Roberto Abate].

"As always in the event of an air crash and when French nationals die abroad, a preliminary enquiry has been opened for which the air transportation police is in charge and with whom the production is fully cooperating."