Daimler questions emission tests on C-class Mercedes

German luxury carmaker Daimler-Benz has described as "questionable" results of emissions tests from one of its Mercedes diesel models cited by a German environmental lobby group on Wednesday, agencies reported.

The group, DUH, said nitrogen oxide emissions of a Mercedes C-class 200 CDI model had been found to exceed Euro-5 limits during tests carried out by the University of Applied Sciences in Bern, Switzerland.

A Daimler spokesperson said: "The test results are questionable as the conditions of the test are not clear. We don't know the specific car, the temperature at the time of the tests, the loading weight."

Fellow German carmaker VW is engulfed in a scandal after rigging results of diesel exhaust emissions tests in the United States.