Germany's biggest carmakers are being investigated on suspicion of operating a secret technology cartel for the past 20 years that led to the dieselgate emissions scandal, it was claimed today.
Daimler, BMW, Volkswagen and the two VW subsidiaries, Porsche and Audi, have been meeting in secret to agree on the technology they will offer their customers, according to allegations published in Spiegel magazine.
The collusion was a direct cause of the diesel emissions scandal, which emerged at VW two years ago, after the five carmakers agreed to limit genuine emissions cleaning technology, the magazine alleged.
The companies are now under investigation by both the German anti-trust office and the European Commission over the allegations, it claimed. Authorities have declined to confirm the report, citing ongoing investigations.
The explosive claims come at the end of a bruising week for the German car industry, which has already seen the emissions scandal threaten to engulf more brands.
Daimler AG has recalled more than 3m Mercedes-Benz diesel cars to lower their emissions, while Audi on Friday announced a recall of 850,000.
But the latest allegations could prove even more damaging. Share prices in the carmakers fell sharply in the wake of the claims: VW dropped as much as 4.9pc; BMW 3.4pc; and Daimler 3.2pc.
German anti-trust authorities discovered the technology cartel by chance last year, Spiegel claimed. During a raid on VW offices to investigate suspicions of a separate steel cartel, investigators chanced upon documents showing the collusion.
The German cartel office confirmed the raid had taken place but declined to comment further, citing ongoing investigations. After the raid, both VW and Daimler made voluntary admissions of guilt to both the German and EU anti-trust authorities in an attempt to avoid penalties, according to Spiegel.
The five carmakers have been "co-ordinating the development of their vehicles, costs, suppliers and markets for many years, at least since the Nineties, to the present day", the magazine quoted the VW admission as saying.
Engineers from the five companies met "regularly several times a year" to discuss technology.
Details of the alleged Daimler admission have not emerged. The collusion began in the Nineties in order to give the German carmakers an edge over rivals abroad, according to Spiegel. The report cites an example of the carmakers agreeing to limit the operation of convertible roofs while a car is moving to speeds up to 30mph (50km/h).
The most damaging allegations concern diesel emissions. The five carmakers agreed to limit the amount of a chemical cleaning agent they fitted, in order to save costs and space, the report claims.
The agent in question, AdBlue, filters some of the most harmful emissions from diesel engines. Before the agreement, some of the carmakers were testing AdBlue tanks as large as 35 litres (1,232 fl oz) on their cars, which could clean emissions for up to 30,000km. But in 2006 the carmakers agreed to limit AdBlue tanks to just 8 litres, which can effectively clean emissions for less than 6,000km, the report alleges.
The carmakers declined to comment on the claims.
"We do not comment on speculations and allegations," VW said.
"We do not comment on speculations on principle," Daimler said.
"We do not engage in such speculations," BMW said.