Rupert Stadler, the chief executive of the luxury carmaker Audi, has been detained over the emissions cheating scandal called Dieselgate, its parent company Volkswagen said on Monday. Last week, Stadler’s private residence was searched for evidence in support of an investigation on charges of fraud and indirectly providing false certification. Prosecutors allege that Audi sold at least 210,000 diesel-engine cars fitted with cheat software in the US and Europe from 2009 onwards. Prosecutors in Munich said the arrest warrant against the Audi chief is based on concealment of evidence. Stadler has denied any wrongdoing.