Volkswagen AG said an internal probe in the wake of the diesel scandal that has engulfed the company for the past six weeks showed irregularities on an additional 800,000 cars, deepening a crisis that has already cost long-time Chief Executive Officer Martin Winterkorn his job, depressed the stock price and led to ballooning provisions.

The German carmaker said the economic risk stemming from the finding is about €2 billion ($2.2 billion), according to a release on Tuesday, citing preliminary estimates. Volkswagen, based in Wolfsburg in northern Germany, said the revelations surfaced following a "comprehensive investigation to establish whether there were indications of further irregularities" after the initial findings rocked the company in September.

"The board of management of Volkswagen AG will immediately start a dialog with the responsible authorities regarding the consequences of these findings," Volkswagen said. "This should lead to a reliable assessment of the legal, and the subsequent economic consequences of this not yet fully explained issue."