More than 650 Volkswagen diesel vehicles registered in Singapore have the type of engine and software called into question in the global emission scandal.
The car manufacturer reported the numbers to the National Environment Agency (NEA) but said yesterday that these vehicles are "technically safe and roadworthy".
The German automaker confessed last month that as many as 11 million vehicles worldwide had the software allegedly used to cheat emission tests, leading to chief executive Martin Winterkorn's swift resignation. The rigging allowed its diesel cars to produce up to 40 times more pollution than allowed.
Volkswagen Singapore said it will directly contact the owners of the 662 affected vehicles, made up of 441 passenger cars and 221 commercial vehicles, to rectify the issue after its headquarters comes up with a technical solution. This will be done at no cost to customers.
The 662 vehicles were fitted with the Type EA 189 EU5 diesel engine and defeat device.
Sales of the affected model - a Touran Multi-Purpose Vehicle (MPV) - were stopped last month.
Asked if these vehicles flout environmental guidelines and ought to be banned, NEA said its top priority is to ensure that Volkswagen provides the necessary rectification works for affected vehicles.
Vehicles imported for sale "are required to comply with the emission standards specified by the European Union or the Japanese authorities", said an NEA spokesman.
"The use of defeat devices has caused nitrogen oxide levels to go up to as high as 40 times the allowable emission limits... It is a precursor of ozone in the environment and can cause respiratory problems. Singapore's nitrogen dioxide levels have, however, remained low and within the World Health Organisation air quality guidelines."
In a separate statement, NEA said approval for all affected Volkswagen diesel vehicles has been suspended and no new registrations will be allowed. The suspension will be in place until Volkswagen has rectified the problem, it said.
There are more than 22,000 Volkswagen vehicles in Singapore.