TOKYO (Kyodo) -- 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 for falsifying product quality data.
Mitsubishi Aluminum Co. and auto-parts manufacturer Diamet Corp. were among the companies searched by prosecutors in July. The headquarters of Mitsubishi Materials were also raided as a related organization, 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 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's president Mutsumi Yasutake stepped down from the post. He was found to have ordered a cover-up of the data falsification and told subordinates to continue shipping products that did not meet customer specifications.
Mitsubishi Aluminium was found to have already engaged in the data cheating in the 1990s.
In launching its raids on the Mitsubishi Materials subsidiaries, the Tokyo District Public Prosecutors 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 delivering products with documents leading to misunderstanding about the quality of the products. Violations can result in a prison term of up to five years or a fine of up to 5 million yen ($45,110) or both for individuals. Companies also face a fine of up to 300 million yen.