Shares in Renault have dived after anti-fraud units conducted raids on the carmaker that unions are reportedly linking to the Volkswagen emissions scandal.

French media reports said the CGT Renault union released a tract Thursday describing raids on multiple sites focusing on engine monitoring that suggested a Volkswagen link.

Soon afterward, the Renault share price sank 22 percent before rallying slightly. It was trading at 69.70 euros in early afternoon. Peugeot shares also fell.

An official with the French Finance Ministry's anti-fraud unit confirmed it had conducted raids on Renault last week but would not elaborate on why. The official was not authorized to be publicly named.