Overview

• Chengxuan Han, a Ph.D. student at Huazhong University, was arrested on June 8 at Detroit Metropolitan Airport on federal charges of attempting to smuggle undeclared biological materials to a University of Michigan lab.
• Prosecutors allege that between September 2024 and March 2025 she mailed four packages containing nematode growth medium and plasmids related to roundworms, mislabeling them as plastic cups and a book.
• According to court documents, Han admitted to making false statements to Customs officers and deleting electronic device contents days before her arrival in Michigan.
• She faces up to 20 years in federal prison and is due back in court on June 13 for a detention hearing to address allegations that federal officials describe as a direct threat to U.S. research security.
• This arrest follows the June 3 detention of fellow scholar Yunqing Jian and a July 2024 smuggling case against Zunyong Liu, spurring the University of Michigan to review security protocols in response to heightened scrutiny of foreign researchers.