Nissan is already under pressure following the arrest of its chairman. (Photo: AFP/Riccardo Savi) |
The latest issue was uncovered after transport ministry officials conducted on-site inspections at Nissan's major assembly plants, the Nikkei business daily said.
Several employees admitted they carried out "improper" tests on brake and other systems before shipment, the newspaper said, without specifying how many cars were affected.
Nissan plans to make an announcement on the case later this month and is considering recalling any vehicles improperly tested, it added.
Immediate confirmation of the report was not available.
The manufacturer was forced to recall more than one million vehicles last year after admitting staff without proper authorisation had conducted final inspections on some units intended for the domestic market before they were shipped to dealers.
In a separate case that erupted in July, Nissan admitted data on exhaust emissions and fuel economy had been deliberately "altered", hampering its efforts to recover trust after the inspection scandal.
If confirmed, it would represent another blow to the company, which has been rocked since Ghosn was arrested on Nov 19 on allegations he under-reported his salary by millions of dollars over five years.
Ghosn denies any wrongdoing.
The ousted chairman is expected to face a further accusation of under-reporting his salary by about four billion yen (US$35.5 million) over the past three years, Japanese media reported.
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