Toyota's handling of potentially deadly accelerator pedal defects came under fresh scrutiny Monday after the company said it had fixed the flaw in Europe last year but initially decided against a global recall.

Toyota's woes are set to deepen this week when the world's largest auto maker is expected to pull as many as 300,000 Prius hybrid vehicles because of a separate issue with the braking system.

The brake trouble comes on top of recalls of more than eight million vehicles worldwide due to sticking accelerator pedals that have severely tarnished the Japanese giant's reputation for reliability.

The company, whose brand has long been synonymous with safety and quality, faces a class-action lawsuit on behalf of owners in the United States alleging that it hid problems that have led to the rash of recalls.

And Toyota's North America president, Yoshimi Inaba, is set to testify at a US congressional hearing on Wednesday as part of a wider probe by lawmakers.

"We did fix this in August last year (in Europe) after first hearing about the issue at the end of 2008," said Toyota spokesman Paul Nolasco.

But it was initially thought that the problem only affected European right-hand drive vehicles, sold mainly in Britain and Ireland, he said.

The trouble was attributed to the car heater blowing hot air on the gas pedal, causing condensation to build up inside and cause sticking, he said.

"The way that the heater air duct is laid out inside right-hand drive vehicles is a little bit different than in left-hand drive vehicles," he said.

Toyota officials could not immediately confirm whether any action was taken at that point for vehicles already on the road in Europe.

Toyota has come under fire after saying it had fixed the brake system flaw during production of the latest Prius model last month, without warning drivers of those vehicles already on the road.

Toyota is believed to have already notified its dealers in Japan that it will pull all the new model Prius vehicles sold in Japan, in a recall that is also expected to affect the United States, Europe, China and other markets.

The Prius -- which combines a petrol combustion engine with a battery-powered electric motor -- is Toyota's flagship hybrid car and key to its efforts to stay in pole position in fuel-efficient vehicles. Related article: Prius woes may muffle hybrid buzz

Toyota, which in 2008 dethroned General Motors as the world's biggest car maker, has seen its brand image badly hurt by its handling of recalls affecting more than its entire 2009 global sales of 7.8 million vehicles. Related article: Toyota recall raises questions about computerized cars

The accelerator problems have been blamed for several accidents, including one in California in August in which four family members were killed.

Toyota vice president Shinichi Sasaki said Friday that when the complaints first emerged in Europe about sticky gas pedals, the company initially thought the trouble did not affect cars sold in the United States.

"In the United States, it was summer at that time. Since the problem occurred due to humidity and condensation, I think there weren't such cases emerging yet in the United States," he said.

But when Toyota began receiving reports of problems in the United States late last year, it took action there as well, Sasaki said.

Company president Akio Toyoda said Friday he was "deeply sorry" for the string of quality issues and said he would head a new task force to raise standards and investigate the cause of the problems.

Despite the ongoing crisis, Toyota shares rose 0.45 percent to 3,330 yen in morning trade Monday, having plunged from above 4,000 yen in just a few weeks.

Toyota has said it expects the accelerator trouble to cost it about two billion dollars this fiscal year in recall costs and lost sales. Related article: Toyota woes a boon for rivals