France's Camille Muffat poses with her silver medal on the podium after placing second in the women's 200m freestyle final with an Olympic record during the London 2012 Olympic Games at the Aquatics Centre in this July 31, 2012 file photo. [Photo/Agencies]

GENEVA -- The International Olympic Committee has mourned the death of three French athletes who were killed in an helicopter crash in Argentina on Monday.

London Olympic swimming champion Camille Muffat, Beijing Olympic boxing bronze medallist Alexis Vastine and yachtswoman Florence Arthaud were among ten people killed when two helicopters collided during the filming of a reality show.

"We are shocked by this sad news," said IOC president Thomas Bach in a statement.

"Our thoughts are with the families and friends of these great athletes who have left us."

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

The IOC said the Olympic flag would be flown at half-mast for three days at its headquarters.

World swimming governing body FINA also expressed its sadness for the death of Muffat, winner of the women's 400m free at the London Games.

"The FINA family is shocked with the dreadful news," said FINA president Julio Maglione.