Several companies constructed their engines in such a way that the pollutant nitric oxide is emitted by their cars unfiltered at low temperatures, the Süddeutsche Zeitung reports on figures obtained from transport authorities.
The evidence comes from testing carried out by the Federal Office of Motor Vehicles (KBA), which conducted the examinations on cars made by Mercedes producer Daimler, BMW, and Volkswagen, as well as several foreign car manufacturers.
A total of 50 different car models were tested, with many of them failing the legal standard for the protection of the environment, some by multiples of the legal limit.
The Ministry of Transport has already notified several companies that they will have to recall cars to make adjustments to the engines.
The car companies claim that their systems for cleaning pollutants are switched off at low temperatures to protect motors, as is allowed by EU regulations.
But some use this regulation to bend the rules, only having the system switch on when the temperature outside is 10 or 20 centigrade, the SZ claims.
Full results of the testing are yet to be revealed, with the transport ministry wanting to wait until it has the most comprehensive data possible before releasing them to the public.
But the authorities are said to be taken aback by the extent to which car companies have bent the rules.
Official testing of the emissions cleaning systems normally take place at temperatures of around 23 degrees Celsius.
But suspicions that car companies allowed these devices to turn off, or become much less effective, at lower temperatures appeared confirmed when many of the cars were recorded emitting much higher levels of nitric oxide in testing at lower temperatures.
In 2015, Volkswagen became embroiled in a global scandal when US authorities discovered they had installed a so-called defeat device in their diesel engines, which meant that nitric oxide emissions were only cleaned up in the exhaust system when cars underwent official testing.
Recently, Volkswagen bosses came in for heavy criticism after Spiegel reported they were refusing to forgo their annual bonuses – after asking employees to tighten their belts with shorter hours and other cost-cutting measures as the manufacturer fights for its future.