Volkswagen CEO being investigated over market manipulation in 'Dieselgate'

The chief executive of German car giant Volkswagen is under formal investigation for the first time in relation to the emissions scandal which rocked the company in 2015.

Matthias Müller has thus far not been investigated by police reviewing the 'Dieselgate' scandal, which has already cost the carmaker tens of billions of euros.

Müller's predecessor Martin Winterkorn and current chairman Hans-Dieter Poetsch have also come under investigation by German prosecutors.

Volkswagen admitted to having installed emissions cheating software in cars in 2015. The company is in the process of removing the illegitimate software that allowed it to cheat tests, which it insists will inflict no loss of value on car owners in Europe.

The criminal investigation has been underway since February of this year

The criminal investigation has been underway since February of this year, and is being led by the state attorney’s office in Stuttgart.

Müller took over as chief of the company after the scandal went public, but the prosecutors are investigating whether there was a deliberate delay in information provided to investors about the scandal.

Volkswagen's share price dropped sharply in the aftermath of the scandal, and investigators are examining whether executives knew about the scale of malpractice involved before informing shareholders.

The carmaker is owned by holding company Porsche SE and said in a statement that it had fully complied with all disclosure rules.