The Japanese government reportedly has ordered Toyota Motor to make "drastic reforms" after discovering new violations in the automaker's vehicle certification procedures.

In a so-called corrective order, the transport ministry said on site inspections had uncovered widespread, intentional misconduct and irregularities in seven additional models that had not been previously disclosed, Reuters reported.

Toyota said the corrective order instructed it to "make drastic reforms to ensure appropriate certification operations".

The automaker added it was in the process of confirming compliance with requirements for the models involved, and customers did not need to stop using affected vehicles.

Earlier this month, Reuters noted, Toyota said it had not found any new cases of wrongdoing in car model certification applications beyond the ones it had already reported in June.

Toyota and four other vehicle makers had admitted in June they had submitted either flawed or manipulated data when applying for certification of vehicles.

Reuters said Toyota's wrongdoing involved three production models - the Corolla Fielder, Corolla Axio and Yaris Cross - and discontinued versions of four other models, including one Lexus.

Toyota said it was planning to resume production for these models from the beginning of September after the transport ministry confirmed they met compliance requirements.

Reuters added the Japanese automakers conducted the investigation after the transport ministry ordered industry wide checks of certification practices following a safety test scandal at Toyota's Daihatsu compact car unit.

The ministry said six of the seven additional Toyota models with irregularities were also certified in other countries, and it had alerted overseas authorities about the issues.

Four of the additional models - a minivan sold under the names of Noah and Voxy, and the RAV4, Harrier, and Lexus LM - were still in production by Toyota while three are no longer manufactured, Reuters added.