Mitsubishi says it has found evidence that its employees falsified fuel mileage test data for several models of vehicle.

The maker of the eK wagon and Outlander sports-utility vehicle said the inaccurate tests involved 157,000 of its own brand light passenger cars and 468,000 vehicles produced for Nissan.

Company president Tetsuro Aikawa said the misconduct had been reported to the transportation ministry.

The problem was discovered after Nissan pointed out inconsistencies in data. Mitsubishi conducted an internal probe and found data was falsified.

The company's shares plunged after the news.

Mitsubishi Motors struggled for years to win back consumer trust after a scandal in the early 2000s over cover-ups of problems such as failing brakes, faulty clutches and fuel tanks prone to falling off.

The Tokyo-based car maker said the inaccurate tests involved its own-brand eK Wagon and eK Space light passenger cars, and 468,000 Dayz Roox vehicles produced for Nissan.

Mitsubishi found that tyre pressure data was falsified to make mileage appear better than it was.

The company said it would investigate whether data was altered for vehicles sold overseas.