FILE PHOTO: The logo of Nissan Motor Co is seen at its showroom in Tokyo, Japan February 9, 2017. REUTERS/Toru Hanai/File Photo

TOKYO (Reuters) - Shares in Nissan Motor Co 7201.T on Monday slumped about 5 percent to their lowest level in more than a year after the automaker said it would hold a briefing regarding its procedures to measure vehicle exhaust gas at its domestic plants.

Japan’s second-largest automaker said it would issue an explanation about its emissions measurement processes at 0800 GMT, sending its shares down to 999.5 yen each, their lowest since April 2017. Nissan declined to give further details.

Japanese companies have admitted to several cases of data tampering over the past year, tarnishing the country’s reputation for high-quality, efficient manufacturing.

In October last year, Nissan said that for decades uncertified inspectors had signed off on final checks for cars sold in the country, triggering a domestic recall of 1.2 million vehicles.

The automaker blamed staffing shortages for the misconduct, which contributed to a slide in full-year operating profit in the year ended March.

Kobe Steel Ltd 5406.T, which supplies steel parts to manufacturers of cars, planes and trains around the world, admitted last year to supplying products with falsified specifications to about 500 customers, throwing global supply chains into turmoil.

Domestic rival Subaru Corp 7270.T in April admitted that employees had manipulated mileage readings on vehicles for the Japanese market, which followed the surfacing of domestic compliance failings last year.