FRANKFURT — German prosecutors said on Monday that they had opened a fraud investigation against Rupert Stadler, the head of Volkswagen’s Audi division, a widening of a long-running inquiry into the company’s emissions cheating.
Mr. Stadler, whose home was raided by investigators, is the first active member of Volkswagen’s management board to be identified as a suspect in the inquiry. The scandal, which involved cheating on diesel emissions, has already cost the company tens of billions of dollars, and led to the arrest or imprisonment of several key executives.
Volkswagen has admitted that the software used to conceal excess diesel emissions was first developed at Audi, which Mr. Stadler has overseen since 2007. Audi diesels were also among some 11 million vehicles equipped with the software, which was designed to ensure they spewed lower levels of emissions during laboratory testing than during normal driving conditions.
Investigators have raided Audi offices and employees’ homes several times in recent months, and they have said that former members of the management board were suspects, though until Monday they had excluded Mr. Stadler.