Troubles continue for Toyota as federal prosecutors in the United States launched a criminal investigation into its recent recalls and are probing allegations it failed to protect the public.

In prepared testimony at a congressional hearing Tuesday Toyota’s top man in America, Jim Lentz, apologized for the company’s slow response to accelerator and braking issues and its poor communication with safety regulators and customers.

Investigators also believe the government dragged its feet and was slow to respond to 2,600 complaints about sudden unintended acceleration between 2000 and 2010.

Toyota's president, Akio Toyoda, is set to testify at a separate hearing Wednesday and speak to his company's response to problems that led to the global recalls of 8.5 million vehicles, due to accelerator problems and faulty braking systems. Steering problems have also been reported in the Corolla.

The accelerator problems have been linked to five deaths in the U.S.

The company is also facing allegations that it failed to look at the full story when it came to the sticky gas pedals and faulty floor mats.

Rep. Henry Waxman (D-Calif.) claimed that Toyota failed to thoroughly investigate the possibility that an electronics glitch was the cause of the gas pedal issues.

Lentz insists there are no problems with Toyota’s electronic throttle system, but Rep. Bart Stupak (D-Mich.) claims the company made that determination based on information from a flawed study.

Meanwhile, Toyota Canada announced Tuesday it will be installing a brake override system in three additional models.

The vehicles included are 2005-2010 Tacomas and 2009-2010 Venzas. In addition, Toyota Canada will provide the brake override system for owners of 2008-2010 Sequoia vehicles.

The system overrides the accelerator if the gas and brake pedals are pressed at the same time.

Tacomas and Venzas have been recalled for problems with gas pedals getting stuck under floor mats. The Sequoias have been recalled due to sticky gas pedals.

Toyota is offering this service to provide an "extra measure of confidence" for its customers. Earlier Toyota announced the brake override would be installed in 2007-2010 Camrys, 2005-2010 Avalons, and the 2007-2010 Lexus ES 350, 2006-2010 IS 350 and 2006-2010 IS 250 models.

The brake override will be included in all future models, Toyota said.