At least some high-ranking executives at Volkswagen knew a year in advance about a probe into the carmaker’s diesel vehicles that eventually uncovered “defeat devices” that skirted federal emission standards, new internal documents reveal. 

Reuters, citing sources close to the matter, reports that an employee warned VW managers, including now-former CEO Martin Winterkorn, that U.S. regulators would likely look into the company’s diesel engine software during an investigation into pollution levels in May 2014.

The warning came about a year and a half before the Environmental Protection Agency and the California Air Resources Board announced they had found so-called “defeat devices” in more than 500,000 VW cars.

The May 2014 warning, also reported by German publication Bild am Sonntag, was disclosed to executives in a letter from the carmaker’s quality and safety department.

“It can be assumed that the authorities will investigate VW systems to establish whether Volkswagen has implemented test-recognition software,” the German newspaper said, citing the letter uncovered as part of VW’s internal investigation.

Two additional sources told Reuters that they had knowledge of the letter, but were uncertain who else may have seen it.

VW declined to discuss the letter, telling Reuters that it does not comment on ongoing investigations.

This isn’t the first time internal communications have suggested VW executives knew of issues with their vehicles before regulators did.

In September, VW’s internal investigation found at least two incidents in which the carmaker was made aware that the use of defeat devices were against the law.

An engineer allegedly expressed concern in 2011 that using defeat devices was illegal. Separately, another source uncovered internal communications between parts supplier Bosch and VW, with the parts supplier insisting that the software was for test purposes and that using it in regular operation would be against the law.

Volkswagen managers were notified about diesel probe in May 2014: sources [Reuters]

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