The Mercedes-Benz logo is seen before the company's annual news conference in Stuttgart, Germany, February 4, 2016. REUTERS/Michaela Rehle/File Photo

FRANKFURT (Reuters) - Daimler's DAIGn.DE board members are not personally under investigation as part of a fraud probe being conducted by the Stuttgart public prosecutor, a company source said on Tuesday.

The German carmaker and owner of the Mercedes-Benz brand said it was being searched by prosecutors as part of a fraud probe related to false advertising and the possible manipulation of exhaust-gas after-treatment in diesel cars.

The Stuttgart public prosecutor’s office said 23 prosecutors and around 230 staff, including police and state criminal authorities, were involved in searching 11 sites in the German states of Baden-Wuerttemberg, Berlin, Lower Saxony and Saxony on the lookout for data files and evidence.