* Senior EU executive says Brussels "to stop fraud"
* German minister: Working on new, honest auto tests
* Merkel's chief of staff wants guarantee from VW
By Michael Nienaber
BERLIN, Sept 26 (Reuters) - The EU could introduce tougher car emissions tests in the wake of the Volkswagen (XETRA:VOWG) VOWG_p.DE rigging scandal, senior European officials said.
The German carmaker named company veteran Matthias Mueller as its new chief executive on Friday in an attempt to get to grips with a crisis that its chairman described as "a moral and political disaster".
The appointment came as Swiss authorities said they were suspending sales of Volkswagen diesel vehicles that could contain devices capable of cheating emissions tests, including Audi, Seat, Skoda and Volkswagen brand vehicles built between 2009 and 2014. They said this could affect 180,000 vehicles.
European Commission Vice President Frans Timmermans said Volkswagen bosses had to fully come clean about the scandal. "We have to stop fraud, and that's why we have to get to the bottom of this," he told German newspaper Sueddeutsche Zeitung in comments published on Saturday.
He said the European Union could change its laws to introduce stricter emissions tests.
German Environment Minister Barbara Hendricks also said the European Commission and member states were considering stricter rules.
"We are currently working on new, honest measuring methods in Brussels," Hendricks told Handelsblatt newspaper in an interview to be published on Monday.
"We can't just rely on tests in the lab," she said, adding future tests should focus more on normal road conditions.
The close relationship between the German government and the country's car industry has been thrown into the spotlight by the Volkswagen scandal.
Chancellor Angela Merkel's chief of staff, Peter Altmaier, called on Volkswagen to take action to restore public trust in the industry. "We need a guarantee that cars of German manufacturers are in line with the norms, without manipulation," he told Der Tagesspiegel in an interview to be published on Sunday.
Volkswagen could face $18 billion in fines from the U.S. Environmental Protection Agency (EPA) after it admitted using software in diesel cars to cheat emissions tests.
The carmaker has said 11 million vehicles worldwide were fitted with software similar to the kind that allowed the company to rig the U.S. tests, but said it was not turned on in the bulk of them.
Regulators and prosecutors across the world are investigating the scandal, while customers and investors are launching lawsuits. The wider car market has been affected too, with manufacturers fearing a drop in sales of diesel cars and tougher testing.
The U.S. Environmental Protection Agency notified auto manufacturers on Friday that they could require additional tests for "any vehicle" to determine whether it meets emission standards under normal road conditions, not just at controlled testing facilities.