A former Tesla employee has filed a lawsuit against his former employer, alleging that the electric automaker has knowingly sold defective vehicles.

Williams asserts that during his time at Tesla, he witnessed the company failing “to disclose to consumers high-dollar, pre-delivery damage repairs” and that defective models were often sold as used or demo/loaner vehicles.

Adam Williams worked for Tesla as a regional manager in New Jersey from late 2011 to September 2017 and in the lawsuit, filed in New Jersey Superior Court, asserts that he was demoted and ultimately fired after reporting the practice to his superiors.

The plaintiff goes on to claim that he reported the practices to Tesla East Coast Regional Manager Lenny Peake and company vice president Jerome Guillen.

As Williams states Tesla was engaging in illegal practices, his lawyer notes that he should be covered under the whistleblower act which protects employees who report, object to, or refuse to participate in what they think is lawbreaking behavior.

In a statement issued to The Verge, a Tesla representative vehemently denied the claims.

“There’s no merit to this lawsuit. Mr. Williams’ description of how Tesla sells used or loaner vehicles is totally false and not how we do things at Tesla.

“It’s also at odds with the fact that we rank highest in customer satisfaction of any car brand, with more owners saying they’d buy a Tesla again than any other manufacturer. Mr. Williams was terminated at Tesla for performance reasons, not for any other reason.”