Volkswagen chairman under investigation as emissions scandal rumbles on

Chairman and former chief financial officer of Volkswagen Group Hans Dieter Pötsch is under investigation over allegations the company failed to disclose details of its emissions scandal to investors.

The German car-maker was found to have cheated emissions tests for its vehicles in 2015, and is still dealing with the legal fallout from the practice.

Pötsch is being investigated by a prosecutor's office in Brunswick, close to Volkswagen's global headquarters in Wolfsburg. In June prosecutors also made CEO Martin Winterkorn the subject of an investigation due to "alleged market manipulation".

"Based on careful examination by internal and external legal experts, the company reaffirms its belief that the Volkswagen board of management duly fulfilled its disclosure obligation under German capital markets law," Volkswagen said in a statement.

Investors have complained that the full extent of the financial risks arising from the scandal were not made clear to them last September when the scandal first broke.

Volkswagen's bill for legal costs pertaining to the incidents has risen now to $20bn, and that figure could well rise even higher.

It admitted to fixing 11m diesel vehicles with software used to cheat regulations on emissions. The company recently settled a claim with US consumers to the tune of $15bn.

Criminal investigations into the German firm's practices are ongoing in both the US and in its domestic environment.