Emergency services battled to put out the blazing Gulfstream IV, which had earlier been reported as a Mystere-Falcon 20, at Castellet airport, between the Mediterranean cities of Marseille and Toulon.
The dead are two men aged 24 and 61 and a woman aged 30, the source said, adding that the plane crashed on landing at the private airport at Castellet after flying from Nice.
“The plane broke in two, one bit ended up in the lake at the end of the runway and the other bit caught fire,” an air safety official told AFP, requesting anonymity.