The revelation was contained in documents filed Wednesday in U.S. District Court in Southern California as part of an ongoing lawsuit against the automaker.
Plaintiffs' lawyers contend Toyota compelled the owners to sign confidentiality agreements that prevented them from speaking publicly about the issues they encountered, the Associated Press reported.
The cases date back to as far as 2006, and allege that Toyota technicians were able to replicate the incidents of unintended acceleration, in which the vehicles sped up without any input from the driver.
"The deeper we dig into the facts that surround Toyota, the more damning the evidence that Toyota was aware of the issue and failed to act responsibly," said plaintiffs' attorney Steve Berman, AP reported. "The revelation that they bought up the cars in question and prevented the owners from talking about their experience is curious at best, nefarious at worst."
The automaker said it looks forward to defending against the allegations made by the plaintiffs.
Complaints involving unintended acceleration in Toyota and Lexus vehicles resulted in the recall of some 8 million cars in the U.S. earlier this year, in two separate actions.
One of the recalls, involving sticky pedals, resulted in a record $16.4 million fine by federal officials against Toyota for failing to disclose the problem in a timely manner.