Photo/IllutrationMitsubishi Materials President Akira Takeuchi, center, and other company officials apologize at a news conference in Tokyo on Feb. 8 over falsified quality data on products shipped by three subsidiaries. (Kentaro Uechi)

Mitsubishi Materials Corp. said three additional subsidiaries falsified quality data on shipments over the past three years, potentially affecting 18,000 tons aluminum products and 6,500 tons of auto parts.

The subsidiaries--Mitsubishi Aluminum Co., Tachibana Metal MFG Co. and Diamet Corp.--shipped the products with faked quality data to 500 companies, even after the falsified data scandal first surfaced, the parent company said Feb. 8.

The revelation brings to five the number of Mitsubishi Materials’ subsidiaries that shipped products with falsified data. About 750 companies have received those products.

On Nov. 23, Mitsubishi Materials said subsidiaries Mitsubishi Cable Industries Ltd. and Mitsubishi Shindoh Co. had shipped products with faked quality data to 227 and 29 companies, respectively.

After that announcement, the company looked further into the matter and found that the three subsidiaries had shipped additional products with falsified quality data.

According to the company, the three subsidiaries rewrote data concerning the quality or size of the products because the real figures differed from those described in contracts with client companies.

In other cases, the subsidiaries wrote false figures on inspection result papers without actually conducting the promised inspections on the products.

Tachibana Metal and Diamet continued to falsify the data until January this year.

The three subsidiaries said no problems have been found concerning the safety of the products as of Feb. 8, but they are continuing their checks.

Mitsubishi Materials President Akira Takeuchi apologized for the new findings at a news conference in Tokyo on Feb. 8.

When asked if he would take responsibility, he only said, “I will take appropriate action after all of the investigations have ended.”

Mitsubishi Materials started reinvestigations at about 120 factories of its group companies this month.

A special investigation committee whose members include outside directors postponed a report on the results of the investigation from late February to March at the earliest.

So far, the investigation results have shown that quality data falsification had continued at Mitsubishi Cable Industries and Mitsubishi Shindoh since the 1990s. Manuals on how to falsify the data were also found.