The boule de petanque had been left inside the barbecue under the grill along with the hot charcoals as the man cooked in the garden of his home in the town of Boulou, in the Pyrénées-Orientales department of south west France.
The ball heated up to a point when it became so hot it exploded, according to initial reports from firefighters who attended the scene.
The explosion sent metal fragments into the man's face. A doctor was sent to the scene by helicopter and paramedics also attended but were unable to save the man, who died from head injuries.
Three young children, their father and the mother of the victim were also in the garden at the time but were not injured.
Firefighters told FranceInfo they had no idea that the balls used for petanque could explode under searing heat. It was not clear whether the ball had been placed in the BBQ on purpose or had been left there by accident unbeknown to the victim.
Pétanque balls are made from “two major types of steel – carbon steel and stainless steel” that are hollow in the middle and weigh between 600 and 800 grams.