The number of suspects under investigation over the massive Volkswagen emissions scandal has increased from six to 17, German prosecutors said Tuesday. The news comes as Volkswagen CEO Matthias Mueller told employees gathered at the Wolfsburg headquarters that the emissions-cheating scandal will inflict “substantial and painful” financial damage on the carmaker.

Chief prosecutor Klaus Ziehe told Agence France-Presse that “no former or current board members” were among the 17 employees under investigation. The automaker had admitted in September last year that it rigged emission tests by equipping diesel vehicles with “defeat device.” About 11 million cars have been globally affected by the emissions scandal, of which 8.5 million cars are in Europe.

Prosecutors in Braunschweig are investigating the suspects as the automaker is based in Wolfsburg, in the regional state of Lower Saxony, which falls under Braunschweig’s jurisdiction, according to reports.

Mueller said Tuesday that the emissions-cheating scandal will keep Volkswagen busy “for a long time,” adding that the German carmaker has made no attempts to conceal its wrongdoings.

Volkswagen previously announced that it had set aside 6.5 billion euros ($7.3 billion) to cover costs related to the scandal that came to light in September after scientists at a University of West Virginia laboratory tested several of the company’s diesel vehicles and found their carbon emissions were as much as 40 times the legal limit in the U.S.

Volkswagen admitted that it was able to cheat on emissions tests by employing the defeat device that indicated the vehicles’ emissions as far lower than they actually were. Volkswagen is facing separate investigations in the U.S., Germany and France in addition to the company’s internal probe.

Meanwhile, as the probe into the Volkswagen scandal widens, the automaker’s second-largest shareholder said that more “unpleasant news” might emerge.

“We will this year probably every now and then be confronted with unpleasant news related to dieselgate,” Stephan Weil, prime minister of Lower Saxony, which holds 20 percent of Volkswagen’s common shares, said Tuesday, according to Reuters. “The damage will, on balance, not be minor, as much as that can already be said today but Volkswagen luckily has a strong economic substance,” Weil told the gathering at the headquarters that was attended by thousands of workers.

He also reportedly said that Lower Saxony has “no reason” to alter its commitment to Volkswagen.