Subaru Corp. said Friday that it had allowed uncertified staff to perform final quality checks of finished vehicles, the latest case in a series of corporate malfeasance scandals by Japanese manufacturers that have shaken trust in Japan Inc.'s once revered quality.

The Tokyo-based firm's revelation comes on the heels of Nissan Motor Co.'s similar improper inspection scandal, which emerged last month and triggered an order by the transport ministry for the nation's automakers to carry out internal probes of their inspection systems.

Subaru said its internal investigation discovered that trainees who were not yet authorized to be inspectors were involved in quality checks of finished cars at two assembly plants in Gunma Prefecture.