Prosecutors raided Mitsubishi Materials Corp. subsidiaries last month for alleged product data fabrication that violated a law preventing unfair competition, sources close to the matter said Thursday.
The nonferrous metal giant is among a host of Japanese manufacturers mired in product data tampering scandals, including Kobe Steel Ltd., which was indicted in July over the fabrication of quality data.
Mitsubishi Aluminum Co. Ltd. and auto parts manufacturer Diamet Corp. were among the companies searched by prosecutors in July. The headquarters of Mitsubishi Materials were also raided, according to the sources.
In November last year, Mitsubishi Materials announced that its subsidiaries manipulated data to meet customer specifications for products supplied to the aerospace, automotive and electric power industries.
The company launched a probe the following month and released a final report produced by a team of lawyers in March. The report said five group companies fabricated the strength data of aluminum and copper products that were shipped to more than 700 firms.
In February, Diamet President Mutsumi Yasutake stepped down from his post. He admitted to ordering a cover-up of the data falsification and telling subordinates to continue shipping products that did not meet customer specifications.
Mitsubishi Aluminium was found to have already engaged in data cheating in the 1990s.
In launching its raids on the Mitsubishi Materials subsidiaries, the Tokyo District Public Prosecutor’s Office’s special investigation squad judged the search was necessary to get to the bottom of misconduct within the organization, the sources said.
The unfair competition prevention law bans the delivery of products with documents that lead to misunderstandings about the quality of the goods. For individuals, violations can result in a prison term of up to five years, a fine of up to ¥5 million or both. Companies face a fine of up to ¥300 million.