Martin Winterkorn, the former chief executive of the German auto maker Volkswagen, has been charged in Germany over his involvement in the company’s diesel emissions scandal.

The public prosecutor in Braunschweig charged him and four other managers with fraud.

The auto maker said it would not comment on the indictments.

Martin Winterkorn, 71, is already facing criminal charges in the US, but is unlikely to face trial, as Germany does not extradite its citizens.

He resigned soon after the so called Dieselgate scandal erupted in September 2015.

In a statement, prosecutors accused Martin Winterkorn of a “particularly serious” fraud, as well as a breach of competition laws.

They said the former VW boss should have alerted car owners and authorities in Europe and the US about the manipulation of diesel emissions tests sooner.

They also accused Martin Winterkorn of approving a “useless” software update designed to conceal the true reason for the cars’ higher emission levels.

If found guilty, Martin Winterkorn could face a prison sentence of up to 10 years.

VW Emissions Scandal: Former CEO Martin Winterkorn Investigated for Fraud

Martin Winterkorn Could Receive $67 Million Severance Package

Prosecutors did not name the other four senior managers charged.

VW first admitted in September 2015 that it had used illegal software to cheat US emissions tests.

The devices, which allowed cars to perform better in test conditions than they did on the road, were installed on almost 600,000 vehicles sold in the US from 2009 though 2015 and millions more globally.

They came to light after a study of emissions by researchers at West Virginia University in the US.

The Dieselgate scandal sparked investigations in Germany and other countries.

To date, the emissions scandal has cost Volkswagen roughly €28 billion, ($31 billion).

Last month, the US Securities and Exchange Commission (SEC) sued VW and Martin Winterkorn, accusing the company of “massive fraud” over the emissions scandal.

The SEC claims VW misled investors by issuing billions of dollars worth of bonds and securities, without disclosing that it had cheated emissions tests.

VW said it would contest the SEC lawsuit vigorously.