Mitsubishi Materials, a division of one of Japan’s biggest conglomerates, saw shares fall by as much 11% on Friday after admitting to a quality scandal.

Mitsubishi Materials said inspection data was falsified on parts used in aircraft, automobiles and industrial machinery, with potentially more than 250 customers affected.

The firm said the impact of the quality scandal on its financial results “are currently unknown”.

The discovery is the latest in a string of scandals tarnishing the image of corporate Japan and its reputation for precision manufacturing.