“It is understood that Min Zin has been placed under criminal detention by the relevant authorities in accordance with the law on suspicion of engaging in espionage and endangering China’s national security,” Lin Jian, a foreign ministry spokesperson, told a regular news conference.
China has notified the U.S. consulate general in the southern Chinese city of Guangzhou of the arrest, he added.
Min Zin, executive director of the Institute for Strategy and Policy (ISP) - Myanmar, was detained after he flew into Kunming in southwest China, three people with knowledge of the matter said.
They all asked not to be named because of the sensitivity of the issue.
The U.S. State Department and ISP-Myanmar did not immediately respond to requests for comment from Reuters.
“Min Zin was arrested at Kunming airport about two weeks ago,” one of the people said, declining to give further details.
The detention comes as the U.S. and China are working to steady their frayed bilateral relationship following U.S. President Donald Trump’s visit to Beijing last month.
A former student activist who participated in Myanmar’s 1988 democracy movement, Min Zin studied political science at the University of California, Berkeley.
He also helped establish the ISP, which was initially based inside Myanmar but moved overseas following the 2021 coup, when the military ousted the democratically elected government of Nobel Peace Prize winner Aung San Suu Kyi.
The coup plunged Myanmar into a protracted civil war, pitting the military against an array of pro-democracy armed groups and established ethnic armies in a conflict that is closely tracked by Min Zin’s ISP.
The think-tank’s recent publications have focused on Myanmar’s political transition, after junta chief Min Aung Hlaing took over as president following a military-engineered election, as well as the country’s failing economy.
China has publicly backed Myanmar’s new administration, which took office after a widely criticised vote that excluded the country’s main opposition groups, including Suu Kyi’s political party.
(Reporting by Joe Case and Reuters staff; Writing by Ryan Woo; Editing by Jacqueline Wong and Kate Mayberry)

Steve Li Kwai-wah, Senior Superintendent Hong Kong Police National Security Department, speaks to reporters during a press conference outside the Wanchai Police Headquarters in Hong Kong, China, 18 August 2021. Four students from the University of Hong Kong were arrested by national security police on suspicion of advocating terrorism after they attended a meeting in July in which they passed a motion mourning a man who stabbed a police officer before killing himself. EPA/JEROME FAVRE