Driver error may have played a key role in many of the "unintended acceleration" incidents in Toyota cars, the US government's preliminary investigation has concluded.
Toyota faces a string of lawsuits following the recall of more than 10m vehicles worldwide with a string of different faults affecting both acceleration and braking.
So far the US National Highway Traffic and Safety Administration (NHTSA) investigation has only looked into the data recorders of cars involved in unintended acceleration.
But in 35 of the 58 cases under review the driver had not put on the brakes. In another nine, the brakes were applied too late. And in one, the brake and accelerator were both pressed together.
A spokeswoman for the US transport department emphasised that the findings were only "one small part" of a broader investigation. She said research was still taking place to "determine whether there are potential electronic or software defects in Toyotas that can cause unintended acceleration".
In February, federal safety regulators linked erratic acceleration in Toyotas to accidents that had claimed 34 lives over the last decade.
The company's position has been that the cases have been down to pedals occasionally getting stuck under floor mats instead of a mechanic or electronic flaw.