Former VW Engine Chief Arrested, Signaling Widening Emissions Casebr FRANKFURT — An investigation into Volkswagen’s diesel emissions scandal expanded significantly on Thursday after Germanbr authorities arrested a former high-ranking executive of the carmaker, two people with knowledge of the arrest said.br Mr. Hatz, well known in automotive circles because of his previous role as chief of researchbr and development at Porsche, is the second person to be arrested in Germany in connection with the Volkswagen case and the first German citizen.br German prosecutors did not disclose Mr. Hatz’s identity because of the country’s privacy rules, saying onlybr that a suspect in the case was arraigned Thursday morning in Munich in connection with a related investigation of Volkswagen’s Audi luxury car unit.br The executive, identified by German news outlets as Wolfgang Hatz, is a former chief of engine development at Volkswagen.