State prosecutors in southern Germany said today they had searched offices belonging to carmaker Audi over parent company Volkswagen's diesel emissions cheating scandal.
In a statement, Audi said it was co-operating with authorities.
"The execution of the search warrants is meant to clarify which persons were involved in the use of the relevant technology and, where applicable, were involved in providing inaccurate information to third parties", Heidenreich said in a statement.
According to Audi, officials started searches of its offices in Ingolstadt and Neckarsulm, where the carmaker employs about a combined 60,000 people, around 8 a.m. local time (0600 GMT), a spokesman for Audi said.
Audi parent Volkswagen admitted in late 2015 to installing so-called "defeat devices" into 11 million diesel vehicles worldwide, created to reduce emissions of harmful nitrogen oxides when engines were undergoing regulatory tests.
"There is suspicion that devices were built into these vehicles to manipulate emissions readings and conform to U.S. emissions limits, without the buyers being informed", they continued.
Volkswagen's headquarters in Wolfsburg were not spared of the search, and investigators also checked six other unspecified facilities.
Audi is owned by Volkswagen, which has admitted it equipped diesel engines with software and devices that reduced emissions when vehicles were undergoing testing.
Volkswagen shares were marked 1.57% lower by mid-day in Frankfurt and changing hands at €139.77 each, although the stock has risen some 40% since hitting an all-time low in early October 2015 after news of the emissions scandal first broke. Protecting profit at Audi, its biggest earnings contributor, is key for VW Group as it spends money on fixing as many as 11 million rigged diesel cars while maintaining financial firepower to develop electric models and new digital services.
Peter Mertens, senior vice president for r&d at Volvo Car Corp., will take up his position as head of technical development at Audi on May 1, the CEO said, replacing former r&d boss Stefan Knirsch, who left the manufacturer in connection with the emissions scandal. The four ringed brand's leader also noted that the efforts to recover from the scandal are "far from over".