Mitsubishi Materials Corp. said Wednesday that its group company covered up data falsification for about a year after the misconduct was uncovered by an internal probe.
Diamet Corp., a maker of automotive sintered parts, neglected final product quality tests and modified specification data when they did not meet figures agreed upon with clients.
According to a final report on the misconduct compiled by an independent third party, it was unclear exactly when and how the falsification started at Diamet — but it possibly dates back to 1977.