Swimmer Camille Muffat , Vastine 2012 gold medalist , thought to have died . Olympic boxer Alexis Vastine and sailor Florence Arthuad also feared dead . Trio believed to have died alongside five other French nationals in crash . Two Argentine helicopter pilots were also killed during midair collision . Fatal accident happened during filming for survival TV show , officials say . Former Arsenal player Sylvain Wiltord also taking part in show .
Swimmer Camille Muffat , London 2012 gold medalist , thought to have died . Olympic boxer Alexis Vastine and sailor Florence Arthuad also feared dead . Trio believed to have died alongside five other French nationals in crash . Two Argentine helicopter pilots were also killed during midair collision . Fatal accident happened during filming for survival TV show , officials say . Former Arsenal player Sylvain Wiltord also taking part in show .