Shares in German auto giant Volkswagen skidded five percent lower at the start of trade on Tuesday following new accusations in the United States over the massive emissions-cheating scandal.
Shortly after trading began on the Frankfurt stock exchange, VW shares tumbled 5.1 percent to 107.00 euros after US regulators accused the carmaker of fitting illegal "defeat devices" in its larger 3.0 litre diesel engines.
At 0815 GMT, the shares were showing a loss of 3.82 percent at 108.40 euros.
In a scandal that has rocked the automobile sector worldwide since it broke last month, Volkswagen had already admitted including the software, which cheats pollution tests, in smaller 2.0 liter diesels equipped in some 11 million 2009-2015 model year cars worldwide.
But the US Environmental Protection Agency said late Monday it had discovered in its investigation that various six-cylinder 3.0 liter diesel VW Touareg, Porsche Cayenne and Audis from the 2014-2016 model years and distributed in the United States had also been rigged with the software.
Volkswagen denied the accusations.
"Volkswagen AG wishes to emphasize that no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner," it said in a statement.
"Volkswagen will cooperate fully with the EPA (to) clarify this matter in its entirety."