Nissan is recalling 1.2 million vehicles in Japan that were produced between October 2014 and September this year to re-inspect them as they had not gone through the proper final checks.

The Japanese automaker said Monday (2 October) a team, including an independent third party, was investigating the cause of the oversight and promised to prevent a recurrence.

The problem does not affect Nissan vehicles sold outside Japan.

The failure is not believed to have affected vehicle safety as they were final-stage checks, according to the Yokohama-based maker of the March subcompact, Leaf electric car and Infiniti luxury models.

Nissan Chief Executive Hiroto Saikawa told reporters the oversight occurred at all six Nissan plants in Japan. He acknowledged not enough had been done to ensure inspection staff were aware of inspection requirements.

He said the recalls and re-inspections will cost Nissan about JPY25bn (£166.7m, $222m).

The inspection oversight is an embarrassment for Nissan. Nissan temporarily stopped registering new vehicles in Japan last week, after the government notified the company it had noticed inspection irregularities.

Japan's car industry has been hit by a series of scandals but its not alone. Volkswagen AG of Germany acknowledged in 2015, it had equipped its diesel cars with illegal software that enabled cheating on U.S. emissions tests. Volkswagen has agreed to more than $20bn (£15bn) in fines and civil settlements over the scandal.