A group of lawyers asked by Mitsubishi Motors Corp. to investigate mileage cheating at the Japanese automaker found the company set unrealistic goals, but employees simply couldn't say, "No."

The Tokyo-based automaker acknowledged in April it had systematically falsified mileage data on its eK wagon and eK Space minicars, also produced for Nissan Motor Co.

The investigative panel said Tuesday such data falsifying went on for 25 years, and the wrongdoing was systematic and extensive.

The probe found the company lacked a system for checking on the team assigned to improve mileage. The company said employees did not feel compelled to respect the law or fix the wrongdoing, which went on for years.

The government earlier found Mitsubishi had overstated mileage on its vehicles by up to 16 percent.