German prosecutors on Monday said they have put former Volkswagen (VW) Group CEO Martin Winterkorn under investigation over his connection to the growing emissions scandal surrounding the car making giant.
Investigators said the probe would focus on accusations of fraud by selling cars fitted with a software programme designed to defeat regulatory emissions tests, Xinhua news agency reported.
"The focus of the investigation is on the accusation of fraud by the sale of vehicles with manipulated exhaust values," a statement issued by the Braunschweig public prosecutor said.
"With regard to the ongoing investigation no further information can be provided," the statement said.
Winterkorn announced his resignation on September 23 as the company is caught in an emissions scandal that has rocked the auto giant.
The US Environmental Protection Agency (EPA) found the software on VW diesel cars showed false emission data.
The company later admitted that a total of 11 million diesel cars may have been involved in the emissions cheating scandal. It set aside 6.5 billion euros (about $7.2 billion) to cover the costs of the issue.