According to the Chinese Foreign Ministry, the man is suspected of engaging in espionage activities that threaten China's national security.
The suspect is a political analyst at a Thailand-based think tank who researches Myanmar.
An anonymous source with connections to the think tank told AFP that the suspect was arrested in the Chinese province of Yunnan, on the border with Myanmar, in early June.
It is unclear whether the man had ongoing research projects when he was arrested.
Another source with close ties to the detained man says he traveled there to attend a meeting.
Myanmar's junta leader, Min Aung Hlaing, will begin a state visit to Beijing on Monday and will meet President Xi Jinping.
