Burning candles form a heart as people pay tribute to late French Olympic swimmer Camille Muffat in Nice, March 10, 2015. [Photo/Agencies]

A magistrate judge at the site said all 10 bodies had been retrieved from the helicopters' mangled ruins and were being taken to a morgue in the provincial capital.

Two pilots and several members of the ALP-TV production company involved in filming the adventure show "Dropped" for private TV station TF1 were among the dead, officials said.

A spokesman for Argentina's Air Accident Investigation Board said it was too early to determine if human error, mechanical failure or something else was to blame.

Two French investigators, as well as two technical experts, were dispatched to Argentina to help gather evidence.

"CHAMPIONS"

"The whole of French sport is in mourning because we have lost three huge champions," Thierry Braillard, junior minister for sports, town and youth affairs, told RTL radio.

"Florence Arthaud - we all knew her as the 'Fiancee of the Atlantic'," he said, referring to a nickname Arthaud earned through many daring voyages, including a 1990 record for the fastest solitary Atlantic crossing.

TF1 issued a statement expressing solidarity with the victims' families. French media said filming had been suspended and the crew and other contestants were heading back to France.

French news channels and social media were awash with tributes for the three stars.

Guy Muffat, Camille's father, told RTL radio his daughter had had a fantastic life that was cut short too early.