A former employee of Volkswagen in the United States is suing the company, claiming he was fired for calling attention to data deletion in September 2015. Reuters/Denis Balibouse

A former employee of Volkswagen — the embattled car company that is facing investigations in the wake of a scandal over cheating on emissions tests— is suing the company for damages, claiming he was fired illegally for trying to stop a co-worker from deleting data last fall.

The news was first reported by German media. The former employee, who worked at a data- processing center for Volkswagen Group of America in Michigan, said he tried in September to stop a colleague from deleting data, after an order from the U.S. Department of Justice forbade any "routine" data deletion.

In the lawsuit, the former employee claimed that the company in the United States had destroyed evidence related to the scandal over emissions cheating. He sought protection from retaliation under Michigan whistleblower law.

Volkswagen Group of America Inc. | FindTheCompany

A German spokesman for Volkswagen declined to comment on the case, citing the fact that "as a matter of principle" the company didn't comment on legal proceedings concerning labor law, Reuters reported.

The Volkswagen scandal dates back to September, after the U.S. Environmental Protection Agency discovered a so-called defeat device in the company's diesel cars. It turned out that those cars had software that could detect when the cars were being tested and would then improve test results by running the car at subnormal capacity and performance. The trick allowed engines to emit up to 40 times the level of polluting nitrogen oxide allowed in the United States.

The company eventually said that about 11 million cars globally had been outfitted with the software. Volkswagen has launched an internal inquiry and for the month of November said that employees who shared information as part of that investigation would receive amnesty protecting them from being fired, although not from possible criminal charges. The company is also the subject of criminal investigation by German prosecutors.