Photo/Illutration The Hokkaido University of Education’s campus in Sapporo (Asahi Shimbun file photo)

BEIJING--The Chinese government for the first time acknowledged that it has detained a professor who had been working at the Hokkaido University of Education.

Yuan Keqin, a 64-year-old Chinese national, is the subject of an espionage investigation, Chinese Foreign Ministry spokesperson Geng Shuang said at a regular news conference on March 26.

Geng said Yuan has “confessed to the criminal fact” to Chinese national security authorities, and prosecutors are discussing whether to file formal charges.

Geng did not say what exactly the professor is being accused of.

Yuan returned to China from Hokkaido owing to a bereavement in late May 2019. He has not been heard from since the following month.

Yuan’s 28-year-old son and fellow researchers held a news conference at the Hokkaido government’s office in February, expressing their worries and urging Yuan to return to Japan.

Yuan specializes in history of international politics in East Asia. He is originally from Jilin province.