The number of Volkswagen Group vehicles sold in Australia fitted with devices designed to mask the level of emissions has risen to more than 90,000 from 77,000, to include the Audi brand, a media report said.

Volkswagen Australia told Reuters it had set up a website for customers to see if their vehicles, including almost 55,000 Volkswagen branded passenger cars, 5,000 Skodas and about 17,000 Volkswagen commercial vehicles, had the affected EA 189 diesel engines. A spokeswoman for Audi Australia confirmed to the news agency a further 14,000 Audis had also been fitted with the device.

"Volkswagen Group Australia takes this issue extremely seriously and is continuing to gather all the facts from our head office to support any rectification plans in Australia," managing director John White said in a statement.

"We understand the disappointment and frustration felt by our customers, dealers and partners in Australia and apologise for any inconvenience this may cause. We are doing everything possible to fix the problem and will be making further announcements," White added.

Reuters noted Australian regulators have launched an enquiry to determine whether consumers have been misled. They say Volkswagen faces legal action and millions of dollars in fines if found to have breached consumer laws.

"The Australian Competition and Consumer Commission (ACCC) is currently investigating whether Volkswagen and Audi exposed consumers to false, misleading or deceptive representations," said the minister for territories, local government and major projects, Paul Fletcher.