BERLIN (Reuters) -- Volkswagen has dampened hopes for quick results from an investigation into its rigging of diesel emissions tests and said developing a fix for the affected cars rather than finding the root cause of the manipulations is its top priority.
"I understand the desire for speed, but what matters to us instead is to work thoroughly and to not give out false premature results," VW brand sales chief Juergen Stackmann said at a panel discussion on Tuesday.
VW's internal investigation is focusing on as many as 40 employees involved in activities related to the manipulations, one person familiar with the matter told Reuters last month.
Independent investigators led by U.S. law firm Jones Day are looking into documents and computer files dating back as far as 2005 when VW took steps to push diesel-engine technology in the United States, and it could take at least six months to achieve results, VW's chief in the UK, Paul Willis, wrote in a letter to UK lawmakers published on Tuesday.
The scandal erupted on Sept. 18 when U.S. authorities exposed VW's use of "defeat devices" to cheat tests for emissions of nitrogen oxide. VW is facing multibillion-euro costs to remedy the issue after admitting such software was installed in up to 11 million diesel vehicles worldwide.
VW owners have been frustrated as the German carmaker still has not engineered a fix for the diesels. The company has halted sales of cars under investigation which it admits were fitted with software capable of cheating government emissions tests.
"What's at stake at the moment is not to find out why people did something, that will be revealed by the investigations," Stackmann said. "What matters to us primarily is that we can offer full transparency to our customers at this point," he said. "Without the trust of our customers, VW would have never become a great brand.