US vehicle safety officials have said they may never know what happened concerning a widely reported sudden acceleration incident with a Toyota Prius near San Diego last week.

The National Highway Traffic Safety Administration (NHTSA) attempted to recreate the drive taken by James Sikes on I8 in southern California when his accelerator pedal apparently became stuck causing the car to travel at more than 90mph (145km/h). A California Highway Patrol Officer aided Sikes, who eventually brought the car to a stop about 20 minutes later.

IN a statement, NHTSA said: "Our engineers have evaluated Sikes' Prius and recreated the drive that Sikes took. We obtained a copy of the diagnostic data that was read at the Toyota dealership and we are still reviewing that data to better understand what occurred with the car.

"So far, we have not been able to find anything to explain the incident that Sikes reported. Further, the Prius is equipped with a system that detects simultaneous brake and accelerator pedal applications. When the brake applications are moderate or greater, the system will close the throttle allowing the vehicle to slow down and stop. The system on Sikes' Prius worked during our engineers' test drive."

However, the US vehicle safety agency conceded there was very little left of the car's brakes, with the inboard front brake pads "completely gone" and the outboard front pads down to approximately 2mm- 2.5 mm. The rotors were also damaged.

"We would caution people that our work continues and that we may never know exactly what happened with this car," added the NHTSA.

Earlier report here