Japan's transport ministry is carrying out on-site inspections at offices of major used-car dealer Bigmotor. The company allegedly conducted unnecessary repairs and filed fraudulent insurance claims.

Ministry officials began searching 34 of the company's offices in 24 prefectures on Friday morning. The company's special investigative committee had pointed out possible wrongdoings at those locations.

The ministry decided to conduct on-site inspections after questioning five Bigmotor executives, including President Izumi Shinji, about the allegations on Wednesday.

Repair companies are prohibited by law from charging customers for services they did not request.

The ministry may penalize Bigmotor if it confirms illegal acts were committed.