An arbitrator has ruled that Dimitrios Biller, a former Toyota attorney turned whistleblower, can submit internal Toyota documents in court to prove his claim that the company instructed him to hide evidence of product defects from the public.

Biller, who handled product liability lawsuits for Toyota, claims the automaker regularly hid evidence of safety defects from regulators and the public. As part of a “civil racketeering” suit against Toyota, Biller has sought to submit as evidence what he claims are four boxes of internal Toyota documents that prove he was asked to hide facts from plaintiffs during product liability lawsuits.

Toyota sought to keep the documents under seal, but the arbitrator in the case, retired judge Gary Taylor, ruled last Thursday that the documents were admissible under a “crime-fraud” exception.