Chen’s family disclosed in July 2026 that he has been held in China for about 20 months, as Washington presses a wrongful-detention case amid broader U.S.-China security tensions.
China has held Youlin Chen, a 54-year-old naturalized U.S. citizen from Boston, on espionage charges since his arrest in Beijing in November 2024 during what his family described as a personal visit to relatives. Chen, a Chinese-born American seismologist, is accused over work analyzing seismic data to detect North Korean nuclear tests, according to his family, who said the research was publicly funded, openly published and conducted under a U.S. State Department contract. His family went public with the case in July 2026, saying he has been detained for roughly 20 months and is reportedly nearing trial. The U.S. State Department has designated Chen as “wrongfully detained,” while China has said the case is being handled under its domestic law. The detention adds to a wider pattern of national-security scrutiny of academics and researchers in both countries, highlighting another point of friction in an already strained U.S.-China relationship.