Court papers have shown that Toyota Motor Corp. faces a pileup of lawsuits, including a shareholder suit in California over fallen stock values.

Shareholders filed a class-action suit in U. S. District Court in California covering shareholders who purchased company stock between Dec. 22 and Feb. 2.

The Detroit News reported on Monday that the suit claims Toyota misled investors with "materially false and misleading statements," regarding its business forecast or its operations.

Peter Henning, a Wayne State University law professor, said that shareholders frequently file lawsuits when a noticeable error causes stock values to fall. But shareholders will have to "prove knowledge among the corporate management" that the company's statements were misleading.

Henning further said, "Unless something else emerges, it seems that Toyota didn't think that it would be the kind of problem it turned out to be."

At least one suit demands Toyota install brake override systems in more cars than those already involved in massive recalls that were issued in October and January due to sudden acceleration problems. (With Inputs from Agencies)