DETROIT - A consumer advocate set to testify this week in a congressional probe of safety issues at Toyota Motor Corp said on Sunday the automaker had skirted a full investigation of unintended acceleration in its vehicles and faced a risk of growing recalls.

I suspect that we are going to see a series of recalls appear over a period of time here, certainly over the next year, and they are going to address varying issues and varying vehicles, said Sean Kane, founder of the Safety Research & Strategies Inc, a consumer safety group.

A 180-page report the group published on its website Friday found that Toyota had yet to fully identify the causes of unintended acceleration in Toyota and Lexus vehicles that have led to its largest ever recall.

The report found Toyota had limited the scope of earlier probes into unintended acceleration, blamed media attention for driving up the number of complaints and then resorted to the least expensive remedy by recalling floormats.

Some 2,260 consumer complaints for sudden acceleration span many years and a wider range of models than have been covered by Toyota's recalls in recent months, the report found.

The consumer data also suggests the problem cannot be resolved by Toyota's recommended remedy -- replacing a sticky pedal or floormat -- the report found.

Toyota spokeswoman Martha Voss said we are looking at the report, but we are not prepared to comment at this time.

Kane has been called as a witness for a hearing into the Toyota issues by the the U.S. House Committee on Oversight and Government Reform on Wednesday.

The committee also has called U.S. Transportation Secretary Ray LaHood; Yoshi Inaba, president and chief operating officer of Toyota Motor North America; David Strickland, National Highway Traffic Safety Administration administrator; and Joan Claybrook, a former NHTSA administrator, as witnesses.

Safety Research said the report was not funded by attorneys, consumers, advocacy groups or experts with an interest in the subject or produced for litigation against Toyota. It did say attorneys, including one who has brought a wrongful death lawsuit against Toyota, had sponsored some of its research into Toyota sudden acceleration reports.

Toyota has recalled some 8.1 million vehicles worldwide, including its best-selling Camry and Corolla sedans for the repair of sticky accelerator pedals or adjustments to prevent floor mats from entrapping the pedal.

While pedal entrapment by the floormat may be a cause of unintended acceleration, it does not cover all the reported incidents and there is a need to examine Toyota's electronic system for a potential cause, the report said.

Toyota has so far ruled out its electronic drive-by-wire throttle system as a cause of the unintended acceleration complaints filed by consumers, and instead identified mechanical issues as the answer to the problems.

Toyota introduced the electronic throttle control to some models in 1998 and widened its use with the 2002 model year.

NHTSA has said it will investigate whether Toyota's electronic throttle control system could be part of the problem. Toyota has said it found no evidence of any safety problems beyond those covered by recalls under way.

Simply, Toyota's entire argument is: our system cannot fail. And, if the system cannot fail, the fault lies elsewhere, the report said.

Kane said on Sunday there is no one fix, or one answer to the complex issues facing Toyota.

There are a multitude of different problems, Kane said. We have a number of makes and models and different issues are occurring, all resulting in one thing and that's unintended acceleration -- the question is, are they related?

Toyota should provide some safety systems to protect consumers while it works to identify the causes of unintended acceleration, including an override system that would shift vehicles into neutral when the accelerator and brake are depressed at the same time.

NHTSA has asked automakers to provide information on the effectiveness of brake override systems through the industry lobbying group the Alliance of Automobile Manufacturers.

Since 1999, at least 2,262 Toyota and Lexus owners have reported of the uncontrolled acceleration problems resulting in 815 crashes, 341 injuries and 19 deaths, the report found.

(Reporting by Soyoung Kim, additional reporting by David Bailey; Editing by Bernard Orr)