Photo/Illutration Society in China is rapidly changing. (Asahi Shimbun file photo)

A trading company employee detained in China early last year received a three-year prison sentence by a local court for "harming national security," the Japanese Foreign Ministry disclosed.

The man, who is in his 40s, works for Itochu Corp.

He was detained by Chinese security authorities in February last year and later indicted on charges of spying.

A court in the southern city of Guangzhou, Guangdong Province, issued the ruling, which has since been finalized.

The court ordered his financial assets of 150,000 yuan (2.3 million yen, or $21,300) to be seized, the ministry said Nov. 26.

While the nature of the man's actions have yet to be fully revealed, the charge of harming national security includes theft of national secrets and spying.

At the time he was held, he was an employee at the Tokyo headquarters and was apparently on a private trip in China.

A total of 14 Japanese nationals have been detained by Chinese authorities on suspicion of harming national security since 2015, with nine of them, including the man, found guilty.

An Itochu Corp. official said: "We apologize for causing distress for people who are concerned about the fact that one of our employees has been found guilty in China," adding, "We will gather information (on the matter), including the contents of the ruling, through diplomatic channels."

(This article was written by Takashi Narazaki in Tokyo and Yuichiro Masumitsu in Hong Kong.)