US justice authorities have issued a new subpoena to Volkswagen over its emissions cheating under laws governing bank fraud, a person close to the matter said Tuesday.The new subpoena is based on the Financial Institutions Reform, Recovery and Enforcement Act and gives investigators broad scope to investigate the company. The source, who spoke on condition of anonymity, explained that the government is seeking information regarding "clean car" tax breaks and rebates granted customers who bought diesel cars made by the huge German company. Volkswagen has admitted that its Volkswagen, Audi and Porsche diesels marketed as environmentally friendly were equipped secretly with illegal devices that hid above-regulation pollution levels from regulators.Volkswagen is already facing multiple investigations in the United States and other countries regarding the cheating, which affected some 600,000 vehicles in the United States and more than 11 million worldwide. The company is facing potentially tens of billions of dollars in fines and owner compensation. German prosecutors said the number of VW officials targeted in their investigation into the emissions scandal had increased from six to 17.The larger number does not include any former or current board members, they said.