NHK has learned that a Chinese court has sentenced an employee of major Japanese trading house Itochu to three years in prison for harming national security.
The male employee in his 40s was detained by Guangzhou security officials in the Chinese city of Qingdao in February last year. He was indicted and tried behind closed doors.
Japanese Foreign Ministry sources say a court in Guangzhou sentenced the man to imprisonment and a fine of 150,000 yuan, or about 21,000 dollars, on October 15. The sentence has since been finalized.
Chinese authorities have been tightening surveillance over attempts by foreign organizations and individuals to steal state secrets and intelligence.
Anti-espionage legislation was enacted in 2014, leading to a series of detentions of Japanese nationals.
Japan's government has asked China for an early release after each detention.
At least 14 Japanese have been detained in China since 2015.
Nine of them have been convicted. Sources with knowledge of Japan-China relations say two of them have appealed and seven have had their sentences finalized.