A corruption scandal that has rocked Volkswagen, the biggest European car maker, has spread, VW chairman Bernd Pischetsrieder acknowledged in a magazine interview Thursday. "The network of shell companies is larger and more complex than forseen... in all 50 to 60 names have emerged in this affair," Pischetsrieder told the German weekly Stern. Until now, only a few people were under investigation in connection with a corruption scandal that has already led to the resignation of VW's head of human resources, Peter Hartz, and the former head of its works council, Klaus Volkert. The prosecutors' office in Brunswick, northern Germany, suspects two of Hartz's close aides set up a network of companies that were then awarded VW contracts. The prosecutors' office in Brunswick opened proceedings against Volkert on Friday as part of its probe into allegations of fraud, including use of works council funds for pleasure trips and stays in luxury hotels.