So far, only one (now former) top-level Volkswagen executive has paid a significant price for their role in the Dieselgate scandal. That could soon change. Reuters reports that German prosecutors are planning to press criminal charges against former Volkswagen Group CEO Martin Winterkorn for his alleged role in the automaker's manipulation of diesel-emissions testing. Another four executives are also being charged. More specifically, the five are charged with fraud and violation of competition law.

But Winterkorn is also facing accusations of fraud, breach of trust and breaching competition laws because of his failure to act as the company's CEO after it became clear those millions of diesel engines had been rigged. He failed not only to disclose what was happening to the necessary authorities in both the US and Europe, but also to stop further installation of those "defeat devices" in vehicles still on the production line.

He had the opportunity to limit the damage but failed to do so. Even the software update Winterkorn approved in November 2013 – some six months after the existence of the manipulated engines had become exposed – was reportedly "useless and was intended to further conceal the true reason for the increased pollutant levels in normal vehicle operation." That recall also cost VW 23 million euros.

Ultimately, VW was caught in September 2015 using illegal engine control software to cheat pollution tests. You know the rest of the story. So far, VW has paid out nearly $33 billion in fines. US prosecutors already filed criminal charges against Winterkorn, but the chances of him being extradited to the US are slim.

He remains in Germany for now, but he's no longer shielded from criminal charges. He may never be able to set foot on US soil again but now his home country is threatening to put him behind bars for potentially the rest of his life. For the record, Winterkorn is 71 years old. Fighting criminal charges is not how he planned to spend his retirement.