Japan's leading logistics service provider, Nippon Express Co., said Wednesday one of its employees falsified inspection stamps on government-stockpiled rice it had stored, in another case of quality check misconduct involving major Japanese companies.

Trading house Mitsubishi Corp., which entrusted the storage operation it was consigned by the farm ministry to Nippon Express, said the same day it was given a business improvement order by the ministry in May over the misconduct. Mitsubishi said it reported preventive steps it will take to the ministry on Monday.

(File photo of government-stockpiled rice)

Some of the stockpiled rice subject to the misconduct -- 15 bags with 30 kilograms of rice in each -- was shipped to a factory to feed livestock but there have been no reports of health damage, Mitsubishi said. The remainder will be incinerated and none of the affected rice has been shipped for human consumption.

According to Nippon Express, an employee at its office in Hiroshima Prefecture in western Japan falsified inspection stamps and pressed them onto 15 container bags of stockpiled rice, which had been switched to new bags after the original ones became wet due to rain in June 2014.

Nippon Express said similar misconduct affected a total of 251 container bags of rice, which had been changed to new bags after the original bags tore on two occasions, first in February 2015 and then around September 2016.

"We deeply apologize for causing great worry and concern to society and people involved," Nippon Express said in a statement.

The data fraud followed a string of quality data falsifications that have surfaced at major Japanese manufacturers since last year, including Kobe Steel Ltd. and automakers Nissan Motor Co. and Subaru Corp. and most recently at a subsidiary of Hitachi Ltd., Hitachi Chemical Co.

The Japanese government stockpiles around 1 million tons of rice on a regular basis for emergencies such as a major disaster or poor harvest, by purchasing around 200,000 tons a year through a tender and storing it for about five years.