Japan's transport ministry has launched an onsite inspection of the head office of Daihatsu Motor. The automaker is under scrutiny following the discovery of more test data irregularities.

The inspection in Osaka Prefecture comes after Daihatsu reported to the ministry on Wednesday that it had confirmed falsified data. The doctored figures are for all 28 models currently being produced or developed, and 18 others that are no longer in production.

The firm is a fully-owned subsidiary of Toyota Motor. It has confirmed various irregularities with a third-party panel. These include data rigging in brake and collision tests.

The development comes after the automaker was found earlier this year to have rigged door-part tests.

A Daihatsu official says they believe it is necessary for the ministry to see what they have, and that they will fully cooperate and strive to restore trust as soon as possible.

The ministry has ordered Daihatsu to halt shipments of all its models until they are confirmed to meet government safety criteria.