TOKYO -- A Mitsubishi Materials subsidiary has falsified quality data on plastic parts used for aircraft and other industrial products, according to people familiar with the matter.
Mitsubishi Cable Industries has shipped parts that failed to clear quality standards set under its contracts with customers, these people said on Wednesday.
The company will hold a press conference, possibly as early as Friday, to explain how it will deal with the issue.
Another case involving the fabrication of quality data recently came to light at Kobe Steel.
The Mitsubishi Cable scandal involves plastic parts called the "O-ring," which is used as packing to create seals in aircraft and other industrial products.
Mitsubishi Cable is believed to have supplied O-rings to hundreds of industrial manufacturers. Since the falsification of data has occurred over decades, the full revelation of facts about the scandal is expected to take time, the sources said.
No safety problems have occurred as a result of the scandal, they said. As O-rings are considered readily replaceable, Mitsubishi Cable is starting to inform its customers of its plan to correct and resolve the issue.
Mitsubishi Materials is a major Japanese nonferrous metal company with a wide range of business lines, including copper, cement, hard-metal tools and aluminum.
The fabrication of O-ring quality data was discovered through group-wide investigations into the quality of products following the revelation in October of Kobe Steel's falsified data on aluminum and copper products.
Mitsubishi Cable has annual revenue of 29.5 billion yen ($263.7 million) and a workforce of roughly 510.