French carmaker Renault said fraud investigators had inspected three of its sites to look into its vehicle emissions technology - news that wiped billions off its market value in an echo of the scandal engulfing German rival Volkswagen.
Renault said investigations to date had found "no evidence of a defeat device equipping Renault vehicles", in a reference to a type of software program Volkswagen was found to have used by U.S. investigators to cheat emissions tests.
French Energy Minister Segolene Royal, who had ordered tests for emissions technology on French and foreign-made cars, said that there was no sign of fraud by Renault.
"Shareholders and employees should be reassured," she told reporters, adding that defeat-device software had been found only on VW cars and no other brands.
However, preliminary results from the tests also showed that emissions exceeded limits on vehicles made by Renault and by some foreign carmakers, Royal added. She also said other manufacturers in France had been visited by the fraud investigators.
Renault shares fell as much as 22 percent after union officials first said the sites had been searched, prompting the company to issue a statement confirming the inspections.
It said fraud investigators were looking at the way it uses exhaust emissions technology in an additional inquiry of parts and factories that follows an earlier investigation by the French government.
Volkswagen last year admitted to using software to conceal the level of toxic emissions from some of its diesel vehicles in the United States.
It faces billions of dollars in claims from owners of vehicles with similar software installed around the world.