BERLIN (Reuters) - General Motors' (GM.N) Opel division has denied violating European environmental standards after researchers said tests on one of its latest models had shown excessive emissions of nitrous oxide.
German environmental lobby group DUH said on Friday that the emissions from Opel's Zafira 1.6 CDTi multi-purpose vehicle (MPV) had been found "in certain situations" to be up to 17 times above EU limits, citing tests carried out on its behalf by the University of Applied Sciences in Bern, Switzerland.
The University of Applied Sciences also said its tests had found this.
All carmakers have come under increased scrutiny since GM's rival Volkswagen (VOWG_p.DE) admitted to cheating U.S. diesel emissions tests last month, sparking a scandal that wiped about a quarter off its market value and forced out its chief executive.
Opel said it had asked DUH several times to make the test results available before they were made public on Friday, with no success. In a letter to DUH dated Oct. 21 and seen by Reuters, the carmaker said its own tests had shown the Zafira 1.6 CDTi's emission levels complied with EU standard limits.
"The DUH's findings imply a subtle suspicion of manipulation on our behalf," an Opel spokesman said. "We strongly deny this accusation."
DUH said the emissions-testing site at the Bern school mainly performs tests for Swiss authorities. It said it planned to examine other diesel models of German and foreign carmakers designed to meet the latest Euro 6 emission standards.
Reporting by Andreas Cremer; Editing by David Goodman