Winterkorn, ranked among the world's most powerful people according to Forbes, quit due to environmental scandal

German prosecutors have launched a formal investigation into the activities of former Volkswagen AG chief executive Martin Winterkorn, who was running the automaker when he was accused of falsifying environmental test results, Bloomberg reported Monday .

The criminal investigation stems from allegations of fraudulent sales of cars whose exhaust toxicity tests were falsified, the agency reported, citing a letter from the prosecutor's office in the German city of Braunschweig. Braunschweig is located in the state of Lower Saxony, whose administration owns a 20% stake in Volkswagen.

The prosecutor's office is trying to find out who is responsible for the fraud. A similar investigation was launched directly at Volkswagen itself.

Winterkorn resigned as CEO of the company on September 23. The executive committee of the company's supervisory board assured that the general director "was not aware of the manipulation of emissions data."

Winterkorn's place at the head of Volkswagen was taken by former Porsche top manager Matthias Müller.

Winterkorn, 68, was considered one of the best auto industry managers of the early 21st century. In the Forbes ranking of the most influential people in the world in 2014, Winterkorn took 58th place. Year after year, he became either the highest or one of the highest paid CEOs in Germany. In 2014, he earned €16.6 million.

On September 18, it became known that Volkswagen AG, using special software, underestimated the content of harmful substances in the exhaust gases of cars with diesel engines during laboratory tests. The US Environmental Protection Agency suspects that when driving on the road, the actual toxic emissions of Volkswagen and Audi diesel cars were 40 times higher than the limits established by US law.

The emission data manipulation affects 500,000 Volkswagen (Jetta, Beetle, Golf and Passat) and Audi A3 vehicles sold in the United States from 2009 to 2015. All of these cars are powered by a 2.0-litre four-cylinder diesel engine with turbocharger and direct injection (TDI).

In total, up to 11 million cars are equipped with software that allows them to circumvent American environmental standards. Including 2.1 million diesel Audi cars. We are talking about 1.42 million Audi vehicles with EU5 engines in Eastern Europe, 577,000 in Germany and almost 13,000 in the USA. The software that caused the scandal is installed on cars of the A1, A3, A4, A5, A6, TT, Q3 and Q5 models equipped with diesel engines.

The German concern in the United States could face a fine of up to $18 billion.

Germany has launched an investigation into the activities of the former head of Volkswagen