The head of Volkswagen's luxury arm Audi was arrested on Monday, the most senior company official so far to be taken into custody over the German carmaker's emissions test cheating scandal.

Munich prosecutors said Rupert Stadler was being detained due to fears he might hinder an ongoing investigation into the scandal, plunging Volkswagen (VW) into a leadership crisis.

News of the arrest comes as VW's new group CEO Herbert Diess is trying to introduce a new leadership structure, which includes Stadler, and speed up the group's shift towards electric vehicles in the wake of its emissions scandal.

"As part of an investigation into diesel affairs and Audi engines, the Munich prosecutor's office executed an arrest warrant against Mr Professor Rupert Stadler on June 18, 2018," the Munich prosecutor's office said in a statement.