German prosecutors have filed charges against Volkswagen CEO Herbert Diess, Chairman Hans Dieter Pötsch and former CEO Martin Winterkorn, according to a statement Tuesday. The indictment charges the executives with intentionally misleading shareholders by withholding information about the company’s 2015 emissions-cheating scandal.

In September 2015, authorities in the US revealed that Volkswagen had rigged millions of its cars in order to cheat emissions tests. Prosecutors now argue that the three executives knew about the investigation and potential damages at least several months beforehand, and therefore should have disclosed this information to shareholders.

Volkswagen’s investors did not learn about the company’s emissions cheating until the US Environmental Protection Agency (EPA) public announcement in September 2015. The scandal caused VW’s stock price to fall by half, and ensuing litigation has cost the company over USD $30 billion.

Lawyers for Diess, who became CEO only months before the EPA’s announcement, said that the charges are not justified. Lawyers for Pötsch and Winterkorn have also issued statements denying any wrongdoing.

The new charges are part of a larger investigation by German prosecutors into the origins of the emissions scandal. Thirty-five individuals, most of whom are former Volkswagen employees, are currently under investigation.