The Volkswagen Group has confirmed that it intends to pursue a dieselgate damages case against former chief executive Martin Winterkorn and Audi CEO Rupert Stadler.

The German car manufacturing giant said that it had taken the decision following the completion of an internal investigation into the circumstances of the scandal, which it described as “by far the most comprehensive and complex investigation carried out in a company in German economic history”.

The Volkswagen Group said that its case against Winterkorn and Stadler would be made in relation to breaches of the duty of care under stock corporation law.

VW’s supervisory board has alleged that Winterkorn breached his duties of care as former chairman of the Board of Management of the Volkswagen Group by failing to “comprehensively and promptly clarify the circumstances behind the use of unlawful software functions in two-litre TDI diesel engines sold in the North American market between 2009 and 2015”.

It further alleged that Winterkorn also failed to ensure that the questions asked by the US authorities in this context were answered truthfully, completely and without delay.