The world's largest car maker, Volkswagen, is yet to tell the Australian government if it cheated pollution tests for cars sold locally as it scrambles to minimise the fallout of the biggest scandal in its 78-year history. 
The German car maker has admitted that it used "defeat device" software to beat emission tests in labs. It is facing fines of up to $US18 billion ($25.6 billion) from the US Environmental Protection Agency, which alleges the affected diesel engines spewed as much as 40 times the legal limit of pollutants when they were on the road.
Volkswagen says the false tests could have been used on about 11 million cars sold around the world, and the Australian Department of Infrastructure and Regional Development is demanding the company come clean.
"The department is seeking urgent clarification from Volkswagen Group Australia as to whether vehicles supplied to the Australian market use similar software to that used in the US," a government spokesman said.
Volkswagen's Australian subsidiary was not able to confirm if the company had used the software for cars sold locally.
"We are still seeking clarification on this topic from our head office in Germany, and we will be providing further information once we have more details," the VW Australia spokesman said.
Senator Kim Carr, former industry and manufacturing minister in the Rudd and Gillard Labor governments, said "there was no excuse" for Volkswagen's behaviour. "It's a tragic, short-sighted management failure. German engineering is so good, they don't need to cook the books in this way."
But he said he was yet to see any evidence of wrongdoing at its Australian operations.
"They obviously tried to cook the books in America, they have acknowledged that, but I've seen no evidence that they have done the same in Australia.
"The fact is we have different regulatory environments [to the US]."
Australian petrol and diesel passenger vehicles must currently comply with the Euro 5 emission standard.
Australia first adopted the standard in 2013, and it is not due to be implemented in full until next   November.
European nations introduced the Euro 5 standard in 2009 and moved to more stringent Euro 6 rules in 2014. Australia will move to Euro 6 across 2017 and 2018.
VW has insisted that all its new European cars comply with Euro 6 rules.