China has indicted a Japanese man who was detained last year for alleged espionage, a Japanese government source said Monday.
Of four Japanese who were detained by Chinese authorities in 2015 in separate cases on suspicion of spying activities, the man from Sapporo is the fourth to have been indicted.
He was detained in Beijing in June 2015 and later formally arrested on suspicion of endangering China's national security.
China indicted the man in October, according to the source. It remains unclear what the charge against him is now.
Since President Xi Jinping took power four years ago, Beijing has been stepping up its watch over foreign organizations and individuals in the name of protecting national security.
A number of foreign nationals have been detained, especially after a counterespionage law took effect in 2014.
In addition to the four individuals, a Japanese man who had served as the head of an organization to promote friendly ties between the two countries was detained, also on suspicion of endangering China's national security, last July.