Prosecutors in the city of Braunschweig have charged Volkswagen CEO Herbert Diess, as well as non-executive Chairman Hans Dieter Poetsch and former CEO Martin Winterkorn with stock market manipulation.

Volkswagen's supervisory board said in a statement on Wednesday that Diess and Poetsch would stay in office.

Earlier in the day, Volkswagen workers applauded Poetsch at a mass meeting of staff at the company's headquarters, according to a participant, as staff appeared to close ranks behind senior managers.

German prosecutors have accused Poetsch as well as the carmaker's current CEO Diess and former CEO Winterkorn of holding back market-moving information on rigged emissions tests four years ago, raising the prospect of more upheaval at the company as it tries to reinvent itself as a champion of clean driving.

The carmaker's supervisory board has not found any evidence that Diess and Poetsch were too late in informing markets.

"This is why the successful collaboration with the chairman and the chief executive will be continued," the board said in a statement.

The staff meeting at the company's Wolfsburg base had been long scheduled and is part Volkswagen's normal agenda where such meetings usually take place every three months.

The charges show how the German company, which in September 2015 admitted using illegal software to cheat U.S. diesel engine tests, is struggling to move on from a scandal which has cost it more than $30 billion in vehicle refits, fines and provisions.

Under Diess, VW plans to spend 80 billion euros ($88 billion) to buy battery cells and develop electric cars and has struck a broad alliance with Ford to help share development and manufacturing costs.

It has also listed its truck business separately under the name of Traton.

(Reporting by Jan Schwartz; Writing by Arno Schuetze; additional writing by Keith Weir and Tom Sims; Editing by Kathrin Jones/Keith Weir/Jane Merriman)