The FBI arrested a California woman at Los Angeles International Airport on Sunday, accusing her of spying on the son of Taiwan's president on behalf of Chinese officials.
Wanying Zhang, 34, also known as Heather, of Irvine, California, was taken into custody before her planned departure to China. Authorities charged her with acting as an unregistered foreign agent.
Zhang allegedly surveilled Lai Ting-yu, the son of Taiwanese President Lai Ching-te, who is a US resident. The FBI did not directly name the target in its initial statement but later shared a report identifying him as Lai Ting-yu.
According to the Justice Department, Zhang travelled to Seattle in 2025 at the direction of Chinese officials. She allegedly sent them photos, video and licence plate information of the president's son and his family.
Bill Essayli, the first assistant US attorney for the Central District of California, said Zhang "used tradecraft to avoid detection" and never notified the attorney general that she was acting on behalf of a foreign government, which constitutes a federal offence.
It was not immediately clear whether Zhang had retained a defence attorney. She was scheduled to appear in a Los Angeles federal court on Monday.
Taiwan's presidential office described Zhang's alleged actions as a "typical case of transnational repression" and thanked the US government for protecting Taiwanese citizens.
"Our country expresses the strongest condemnation of such barbaric conduct that disregards human rights and the sovereignty of nations," presidential spokesperson Karen Kuo said in a statement.
China's foreign ministry did not respond to a request for comment.
President Lai Ching-te and his Democratic Progressive Party champion Taiwan's separate identity from China, a position that frequently angers Beijing, which views the island as Chinese territory. Lai has stated that only Taiwan's people can decide their future.
Washington does not maintain formal diplomatic ties with Taiwan, but the United States is the island's most important international backer and is bound by law to provide it with the means to defend itself.
