Daihatsu said that an independent committee had found issues involving 64 models, including almost two dozen sold under Toyota's brand. The panel had been investigating the unlisted carmaker after it said in April that it had rigged side-collision safety tests carried out for 88,000 small cars.

Japan's transport ministry is considering administrative penalties against Daihatsu including revoking its production certification depending on its own investigation, the Nikkei business daily reported.

Daihatsu said on Wednesday it did not know when it would resume shipments, but that the impact on its earnings would be substantial.

Shares of Suzuki Motor, Daihatsu's main rival in Japan's minivehicle market, rose more than 2%, while Tokyo's benchmark Nikkei average was down 1.3% as of 0040 GMT.

(Reporting by Kaori Kaneko; Editing by Chang-Ran Kim)