GENEVA, Aug. 8 (Xinhua) -- The Swiss Federal Roads Office announced Wednesday that the new Audi A6 and A7 3.0-litre diesel cars have been refused authorization to drive in Switzerland due to tampering with their anti-pollution control systems.

The vehicles are from Audi's C7 generation, which comply with the Euro 6 standard.

The Federal Roads Office said in a statement posted on its website that the cars have been equipped with illicit devices that tamper with the purification of exhaust fumes.

The emissions scandal involving German car makers first came to light in 2015 when the U.S. Environmental Protection Agency accused Volkswagen of equipping 11 million of its diesel vehicles with software that falsifies the results of anti-pollution tests, the Swiss News Agency, SDA-ATS reported.

These allowed the cars to conceal emissions of up to 40 times authorized levels.

The Audi vehicles named by the roads' office will only be registered in Switzerland as new vehicles once they comply with pollution requirements, the office said.

The ban only concerns Audi vehicles imported starting next week.

"Vehicles already registered in Switzerland are not affected by the registration ban and may, therefore, continue to be driven or to be put on sale on the second-hand market," said the statement.

The 2018 and 2019 models of the Audi A6 and A7 (C8 generation) are not affected.