Sources say Japan's transport ministry plans to issue an order to Toyota Motor to improve its business practices after discovering the company failed to follow vehicle testing procedures for another model.

It came to light in June that Toyota falsified performance test data on seven models to obtain the certification required for mass production. The company suspended the production of three models after the transport ministry ordered it to halt their shipments.

In early July, Toyota said no wrongdoing was found during an internal probe into testing procedures that the firm followed for the past 10 years for domestic models.

But the sources say an investigation by the transport ministry revealed the carmaker falsified data on another model. They say the ministry decided to issue the business improvement order based on the road trucking vehicle law.

This would be the first corrective order issued to Toyota.