Audi CEO Stadler shows the e-tron prototype at a recent press event (Photo: Audi)

Audi appointed Abraham Schott interim CEO following the arrest of Rupert Stadler earlier in the week.

The German premium car maker said Schot, who has headed sales and marketing at Audi since 2017, is taking over immediately.

Audi said Stadler had requested to be relieved of his duties, both as head of Audi and as a member of the supervisory board of its parent company, Volkswagen Group.

"The supervisory boards of Volkswagen and Audi have complied with Stadler’s request to release him from his duties," Audi said in a statement. "This release applies temporarily, until the circumstances that led to his arrest have been clarified," it added.

The Munich public prosecutor's office issued an arrest warrant for Audi CEO Rupert Stadler Monday, as the Volkswagen diesel scandal spread to yet another senior group executive.

In a press release, the office said Stadler was brought before an investigating judge, who ordered him remanded in custody.

Stadler, who has been at the helm of Audi since 2007, has been detained amid fears among investigators that he might suppress evidence material to the continuing diesel emissions inquiry. An investigation into the extent of VW's cheating on diesel emissions has been in progress since 2015.

Audi engines, which are used in other VW Group brands as well, are part of the investigation, the prosecutor's office said in a press release a week ago.

The office said on June 11 that, since the end of May, Stadler and another management board member have been under investigation for fraud and "wrongful certification." The charges relate to the introduction on the European market of diesel vehicles equipped with illegal exhaust control software, the office said.

The number of defendants in the preliminary investigation has risen to 20, it added last week.

Reports that VW had used so-called defeat devices in its diesel-powered cars first came to light in the US in 2015. The software let the cars show much lower emissions during tests than on the road.

Since 2015, VW Group has had to pay billions of euros in fines and has had to reimburse US customers on a wide scale. Most of the group's senior management has also been replaced since the diesel fraud first came to light.

By Arjen Bongard