TOKYO (REUTERS) - Mitsubishi Motors Corp manipulated fuel economy data on an additional model other than vehicles already disclosed and may have also misstated data on four other models, the Sankei newspaper reported on Friday (April 22).

Japan's sixth-largest automaker this week admitted it had overstated the fuel efficiency of 625,000 cars, sending its share price plunging and prompting a raid by Japanese authorities on one of its facilities.

Mitsubishi had said there may be more models that used the same test methods that violate regulations, but it did not elaborate.

The company told Reuters it was checking the report.

Japanese Transport Minister Keiichi Ishii said on Friday he wanted Mitsubishi to respond "with integrity" and look at possibly buying back the cars in question, Kyodo news reported.

Mitsubishi has disclosed it cheated on four models, including two it produces for Nissan Motor, both of which are specifically marketed in Japan.

The Sankei said that Mitsubishi had also manipulated fuel economy data on the i-MiEV electric car, which is also sold overseas. The Sankei said the RVR, Outlander, Pajero and Minicab MiEV models were also suspected of using illegal test methods.

Japan's Transport Ministry ordered Mitsubishi Motors to submit a full report on the test manipulation within a week, and for other Japanese automakers to also submit fuel economy test data by May 18.

Shares in Mitsubishi plunged 14 per cent on Friday to a record low. They have lost roughly 40 per cent over the past three days, amid concerns about the potential cost of compensation and fines from the biggest scandal to hit the company since a defect cover-up a decade ago.