Prosecutors conducted searches at two German factories of carmaker Opel for possible evidence of cheating on emissions tests, the subsidiary of France's Peugeot SA confirmed Oct. 15.

The issue of falsifying emissions testing has plagued the industry since the use of software to doctor results was uncovered at Volkswagen AG in 2015.

"Opel confirms that the public prosecutor's office of Frankfurt is conducting investigations in the course of preliminary proceedings on emissions at the sites in Rüsselsheim and Kaiserslautern," Opel said in a statement posted on its website. "We cannot comment on details concerning the ongoing investigation at this moment in time. The company is fully cooperating with the authorities."

"Opel reaffirms that its vehicles comply with the applicable regulations," the company said.

The investigation seeks to clarify whether software has been used to falsify the emissions figures of 95,000 diesel-engined cars, Reuters reported the Frankfurt prosecutor's office as saying, adding that the engine type the prosecutors are focusing on is used in Insignia, Zafira and Cascada models.

The fraud and competition watchdog within France's Finance Ministry previously investigated Opel for suspected emissions fraud but announced in March 2017 that it had ended its inquiry after finding no evidence of an attempt to falsify emissions readings.

Calls from S&P Global Market Intelligence to Opel's press office were not answered.