Audi CEO Rupert Stadler arrested

Audi CEO Rupert Stadler has been arrested at his home in Ingolstadt over his connection to the Volkswagen Group's Dieselgate emissions scandal.

Stadler was detained in the early hours of Monday morning after prosecutors asked the courts for his arrest over fears he might tamper with evidence.

The shock arrest makes Stadler the highest-profile senior Volkswagen Group executive to be put behind bars in an investigation that began back in September 2015.

Stadler's night behind bars comes less than a week after the authorities raided his house and publicly named him as a suspect for fraud that, it's reported, involved falsifying public documents in relation to selling diesel cars within Europe.

In response to his arrest, it's thought VW Group's supervisory board will suspend its CEO and name current sales head, Bram Schot, as an interim CEO.

Investigators will spend this week questioning Stadler, the Munich prosecutors have announced, suggesting to German media they were worried the Audi CEO might have influenced witnesses in the probe.

Despite not yet being charged of any crime, Stadler could remain in jail for as long as three months as part of a pre-trial detention, but if he chooses to cooperate with the prosecution he could leave custody much quicker.

Last week Volkswagen Group execs had hoped a €1 billion fine from the German government was the beginning of the end of its emissions-cheating saga but Stadler's arrest signals Dieselgate is far from over.

Stadler's involvement is not limited to running the most profitable part of the Volkswagen empire.

The Audi CEO also oversaw the division that provides engines and technologies to a number of the group's brand – including Porsche, which became entangled in the emissions saga after Cayennes fitted with the Audi-sourced 3.0-litre V6 turbo-diesel were found with a software cheat.

Stadler, who has led Audi since 2007 and also sits on VW's management board, initially rejected US investigator claims that his car-maker used a 'cheat device' to unlawfully pass emissions tests.

The writing has been on the wall for Stadler since former Audi engineer, Urich Weiss, told a German court last year that the Audi boss had been aware of the illegal software earlier than he admitted.

According to Bloomberg, VW still faces legal proceedings in 55 countries over Dieselgate. The German auto giant has put aside more than €27 billion to pay fines.

Stadler is not the only Audi exec currently behind bars. Former VW manager Wolfgang Hatz, who joined Audi in 2001, has been in custody in Munich since September.

Another engineer, Giovanni Pamio, also spent time in jail last year and was released four months later after extensive questioning.

According to German investigators, the current probe involves 20 people linked to Audi.

In the US, there have already been two successful prosecutions. The first saw VW engineer, James Liang, plead guilty to conspiracy before he was sentenced to 40 months in jail.

The other was VW compliance exec, Oliver Schmidt, who pleaded guilty to one count of conspiracy to defraud and was given a seven-year sentence.