A Chinese historian who had taught at a university in Hokkaido and was detained by Chinese authorities for espionage has been prosecuted, the Foreign Ministry said Thursday.

But Foreign Ministry spokesman Wang Wenbin did not elaborate the details of the prosecution of Yuan Keqin, a scholar who had worked for Hokkaido University of Education.

Yuan had been out of contact since June 2019 after he returned to China in May that year. The Chinese ministry said in March last year that he was detained.

"He is a Chinese citizen. He was censored by the Chinese national security department for suspected espionage. He confessed to the facts of the crime. The facts of the case are clear and the evidence is conclusive," Wang said.

Since his detention, Japanese scholars have been collecting signatures as part of a campaign to urge the Chinese Communist-led government to release Yuan.