Tokyo/Beijing: A Japanese citizen, detained by the Chinese security forces four years ago, has been sentenced to 12 years for espionage, the NHK broadcaster reported on Friday, citing government sources.

The report said that the man, who was around 5 year old, was detained in July 2019 in Changsha, the capital of China's Hunan province.

The detainee was later indicted, but the charges were unknown, the broadcaster reported.

The man was sentenced on February 8, according to the report.

At least 16 people have been detained in China since 2015 on suspicion of involvement in espionage and other activities, and about 10 people, including the Japanese citizen in question, have received a prison term, it added.

(With UNI inputs)