A Qatari diplomat has been recorded driving at three times the speed limit in the tunnel linking France to Italy.
Concerns remain about tunnel safety following the 1999 tragedy
The man - who has not been named - is believed to have broken the record for the fastest time recorded in the Mont Blanc tunnel.
His car was doing 214 km/h (125 mph) in a 70 km/h limit.
Speed limits are strictly enforced since the tunnel reopened in 2002, after a vehicle fire turned it into an inferno, killing 39 people.
The fire in March 1999 led to a complete renovation of the 11.6km (seven-mile) tunnel and the addition of numerous safety features including devices to monitor vehicle speeds.
The speeding incident took place just before midnight on 16 April, but details have only just emerged in the French Media.
Dauphine Libere, a regional newspaper, identified the driver as a secretary at the Qatari embassy but did not name him.
The Mont Blanc Police confirmed the story to BBC News Online but were unable to supply further details. The Qatari embassy in Paris was contacted, but did not provide a statement.
It was established that the driver had diplomatic immunity when he was stopped by the police. The case has been passed to the public prosecutor's office in Bonneville.