Mitsubishi Motors Corporation (MMC) has admitted to falsifying fuel use figures for four vehicles sold in the Japanese market.
The Japanese brand has confirmed that the "fuel consumption testing data submitted to the Ministry of Land, Infrastructure, Transport and Tourism (MLIT)" saw vehicles tested "improperly to present better fuel consumption rates than the actual rates".
A statement from Mitsubishi Motors also confirmed that "the testing method was also different from the one required by Japanese law".
The four models affected by the falsified fuel consumption figures are mini-car models: two variants of the eK - the eK Wagon and eK Space - both of which are sold solely as Mitsubishi products; and two other models built by Mitsubishi but sold as Nissan products as part of an alliance, the Dayz and Dayz Roox (pictured below).
The four vehicles have been on sale since June 2013, and Mitsubishi claimed it has sold 157,000 examples of the eK model and Nissan Motors (NM) has sold 468,000 examples of the Dayz.
"Since MMC developed the applicable cars and was responsible for obtaining the relevant certifications, MMC conducted fuel consumption testing. In the process of the development for the next generation of mini-car products, NM examined the fuel consumption rates of the applicable cars for NM’s reference and found deviations in the figures," the statement read.
According to MMC, it was requested by Nissan to check the running resistance - rolling resistance of tyres and air resistance of the vehicle while moving.
"In the course of our internal investigation upon this request, MMC learned of the improper conduct that MMC used the running resistance value for testing which provided more advantageous fuel consumption rates than the actual rates," the statement continued.
The company will issued an apology to owners, and production of the affected models has been ceased, while sales of the Nissan vehicles has been halted. Mitsubishi "will discuss compensation regarding this issue" with Nissan.
Mitsubishi has also found that "the testing method which was different from the one required by Japanese law has been applied to other models manufactured by MMC for the Japanese domestic market".
The company has confirmed that it will "conduct an investigation into products manufactured for overseas markets".
"In order to conduct an investigation into these issues objectively and thoroughly, we plan to set up a committee consisting of only external experts. We will publish the results of our investigation as soon as it is complete," the statement concluded.
Mitsubishi shares fell sharply following the announcement, with 15 per cent - or US$1.2 billion - wiped from its market value.
Mitsubishi Motors Australia has echoed the statement made by the company's Japanese headquarters, and in a statement said that the investigation into models sold in international markets "will be conducted by a committee of experts operating independently of Mitsubishi Motors".
"In the meantime, MMAL will continue to monitor the situation closely," the statement read.
Stay tuned for more.