Mitsubishi Motors Corp., the Japanese automaker under investigation for lying about fuel economy data for some models, says such tampering is suspected in all of its vehicles sold in Japan.

The company has said it carried out false tests and gave inflated mileage on minicars known as "kei," whose production began in 2013, called eK wagon and eK Space light passenger cars under its own brand and Dayz and Dayz Roox that it produced for Nissan Motor Co.

The company said Wednesday the extent of such fraudulence was wide, possibly affecting all current and discontinued models.

The latest scandal surfaced last month after Nissan pointed out discrepancies with its own mileage tests. Mitsubishi also was embroiled in a massive scandal 15 years ago involving a systematic cover-up of auto defects.