Mitsubishi Motors denied Thursday equipping engines with devices to make them appear less polluting, after raids by prosecutors in Germany probing suspected diesel emissions cheating.

The probe focuses on Mitsubishi diesel vehicles with 1.6- and 2.2-litre engines that were given Germany's highest Euro 5 and Euro 6 ratings on emissions standards.

Prosecutors suspect they are equipped with a so-called "shutdown" or "defeat" device that makes engines appear less polluting in tests than they are on the road.

In a statement, Mitsubishi said the 1.6-litre diesel engines examined in the January 21 raid were manufactured by PSA Group, which owns brands such as Peugeot and Citroen.

It did not specify who was responsible for making the 2.2-litre engines, but said "no engines manufactured by Mitsubishi Motors are equipped with a so-called 'defeat device'".

Mitsubishi Motors has denied equipping engines with devices to make them appear less polluting during tests
Mitsubishi Motors has denied equipping engines with devices to make them appear less polluting during tests AFP / Behrouz MEHRI

The firm said it had been "fully disclosing" its engines and control systems to German authorities and "making improvements whenever any indications are made".

"We have found no reason to believe that there was any fraud as suspected by the Frankfurt Public Prosecutor authorities," the statement added.

The Mitsubishi probe is the latest twist in the "dieselgate" scandal that erupted in 2015 when the Volkswagen group admitted to installing software in 11 million vehicles worldwide to dupe pollution tests.

The "defeat devices" allowed the affected cars to spew out up to 40 times more harmful nitrogen oxide than legally allowed.

The scandal has since ensnared a string of car companies, although Mitsubishi Motors had so far avoided being dragged into the controversy.

But the Tokyo-based firm did in 2016 admit to falsifying fuel-economy tests for 25 years to make the cars seem more efficient than they were.

Germany