Record-breaking French free-diver Loic Leferme died in an accident while training in the Mediterranean Sea, according to a statement posted on his website.
Leferme, 36, was training off the southeastern town of Villefranche-sur-Mer on Wednesday, when his system of counterweights failed, the statement said. He dove to 170 metres and was resurfacing when the accident happened, the statement said.
He was unconscious when he was brought to the surface. He was evacuated to neighbouring Nice, where emergency workers tried unsuccessfully to resuscitate him for 45 minutes.
Leferme broke the world record for free-diving in 2004 with his unassisted dive of 171 metres.