TOKYO, April 6 (Reuters) - Japanese automaker Nissan Motor has lost access to a tax break for companies that raise wages after unlawfully underpaying dozens of suppliers, the Yomiuri newspaper reported on Saturday.

Nissan had been using the tax break and will be ineligible for at least a year, the newspaper reported. The tax measures were expanded by the Kishida administration as part of efforts to encourage companies to raise wages, the Yomiuri reported.

Japan's fair trade watchdog said last month Nissan had unlawfully underpaid 36 suppliers by about 3 billion yen ($20 million) over a roughly two-year period from January 2021.

The automaker said it had refunded suppliers and would strengthen its inspection system.

Nissan did not immediately respond to request for comment outside of business hours.

($1 = 151.6100 yen)

(Reporting by Sam Nussey. Editing by Sam Holmes.)