Bannister Law has filed two class actions under consumer law in the Federal Court against VW and Audi for selling vehicles that contained emissions defeating devices.

“In supplying cars containing the defeat device, the statutory guarantee was not complied with,” class principal Charles Bannister said in a statement today.

“If we’re successful on that part of the claim, the customer may be entitled to a refund of the purchase.”

More than 100,000 local cars have been caught up in the German carmarker’s global emissions-rigging scandal.

In September, when news of the emissions scandal broke out, VW’s shares plummeted nearly 20 per cent when it was found that hundreds of thousands of its diesel cars have software that secretly thwarts US pollution tests.

VW, the world’s largest carmaker by sales in the first half of this year, said it had halted all diesel vehicle sales in the United States during a probe into the scandal, which could lead to fines of more than $US18 billion ($A25.23 billion).

In addition to the environmental fines, US authorities have reportedly launched a criminal investigation into the company.

According to the US authorities, VW admitted that it had equipped about 482,000 cars in the US with sophisticated software that covertly turns off pollution controls when the car is being driven and turns them on only when it detects that the car is undergoing an emissions test.

With the so-called “defeat device” deactivated, the car can spew pollutant gases into the air, including nitrogen oxide in amounts as much as 40 per cent higher than emissions standards, said the US Environmental Protection Agency.

-AAP