Toyota officials continued to insist Tuesday that consumer complaints regarding unintended acceleration in their cars has nothing to do with the vehicle's electronic systems as some have suggested.

"I want to be absolutely clear,” Takeshi Uchiyamada, an executive vice president for the Toyota Motor Corporation, testified before a Senate committee, the third congressional hearing on the automaker's problems.

“As a result of our extensive testing, we do not believe sudden unintended acceleration because of a defect in our ETCS (Engine Throttle Control System) has ever happened. However, we will continue to search for any event in which such a failure could occur."

His testimony came as federal safety officials increased the number of reported deaths linked to the acceleration issue in Toyota vehicles to 52 through the end of last month.