Tokyo prosecutors said Wednesday they have indicted three subsidiaries of Mitsubishi Materials Corp. and the former presidents at two of the units over suspected product data fabrication.

The subsidiaries — Mitsubishi Cable Industries Ltd., auto-parts manufacturer Diamet Corp. and Mitsubishi Aluminum Co. — allegedly violated a law preventing unfair competition, according to the prosecutors.

Hiroaki Murata, the 61-year-old former president of Mitsubishi Cable, as well as Mutsumi Yasutake, the 60-year-old former head of Diamet, were also indicted for their suspected involvement in the data falsification.

The prosecutors raided the Mitsubishi Materials units in July after the nonferrous metal giant announced in November last year that its subsidiaries manipulated data to meet customer specifications.

Aluminum and copper products with fabricated strength data were shipped to more than 700 firms, according to a probe launched by Mitsubishi Materials.

Other Japanese manufacturers have been mired in similar scandals, including Kobe Steel Ltd., which was indicted in July over the suspected falsification of product quality data.