Vauxhall has denied claims by BBC Panorama that a Zafira model failed EU emissions tests.
The television programme showed a Vauxhall Zafira people carrier pumped out two and a half times more polluting nitrogen oxide than is allowed in a lab test.
Vauxhall says it does not use cheat software similar to that found on Volkswagen cars and called for Panorama to release details about the test.
A Vauxhall statement says: "Vauxhall products comply with all regulatory requirements, including the in-service emissions testing program, according to EU rules. These requirements are periodically audited by the approval authority.
"We suspect that the vehicle tested (Zafira 1.6 diesel) was not performing correctly and/or the test execution was not correctly set up."
Vauxhall wants information on the technical accuracy of the test but says Panorama refused prior to broadcast.
It says: "When DUH tested the Zafira in Germany they were not willing to share their results before they went public. We subsequently concluded that the campaign contained misleading elements. In response to the incorrect accusations of DUH we ran a full series of tests. Those tests proved that the Zafira 1.6 meets all the legal emission limits both in 2WD and 4WD roller testing."
The Volkswagen emissions scandal has rocked the motoring industry in recent months after it was discovered certain Volkswagen diesel models, including the popular Golf hatchback, used software to deliver artificially low emissions in official US tests.
Other car makers have not been implicated in the scandal, however the Vauxhall Zafira has been in the news after reports of Zafira B models bursting in to flames. Vauxhall has sent letters to 220,000 affected owners with details of checks on the cars.
