The two defendants said they would not challenge prosecutors’ request to keep them in detention while their cases progress.
Two Chinese nationals accused of smuggling restricted biological materials into the United States will remain in custody after waiving their right to a hearing in separate court appearances in Detroit on June 13.
Han Chengxuan, a doctoral candidate from China’s Huazhong University of Science and Technology in central China’s Wuhan city, and Jian Yunqing, a post-doctoral research fellow at the University of Michigan, allegedly smuggled the materials for use at the University of Michigan.
On Friday, the two defendants said they would not challenge prosecutors’ request to keep them in detention while their cases progress.
“This is a constantly evolving situation involving a large number of factors,” Han’s attorney, Sara Garber, told a judge. Garber didn’t elaborate and later declined to comment.
Jian’s attorneys declined to comment Friday.
Han was arrested upon landing at the Detroit Metropolitan Airport on a flight from China on June 8. She arrived on an exchange visitor visa and planned to spend a year at the University of Michigan for a research project on roundworms.
At the airport, Han allegedly made false statements to customs officials about packages she had sent to individuals at a University of Michigan laboratory. She eventually admitted that the packages contained biological roundworm-related materials.
According to the criminal complaint, the packages did not contain the correct documentation and were not imported under the Department of Agriculture or Customs and Border Protection regulations.
In response to Han’s case, FBI Director Kash Patel called out the Chinese Communist Party (CCP) in a post on the social media platform X on June 9.
“This case is part of a broader effort from the FBI and our federal partners to heavily crack down on similar pathogeon [sic] smuggling operations, as the CCP works relentlessly to undermine America’s research institutions,” Patel wrote.
Yesterday, @FBIDetroit arrested a second Chinese national on charges of smuggling biological materials into the U.S. and lying to federal agents.
— FBI Director Kash Patel (@FBIDirectorKash) June 9, 2025
This individual is Chengxuan Han, a citizen of the People’s Republic of China and a Ph.D. student in Wuhan, China. Han is the third… pic.twitter.com/TE4tJgtJQi
Several Republican lawmakers took to X to echo Patel’s concerns in response to Han’s case.
“Never forget: the CCP is ACTIVELY trying to undermine the U.S. and DESTROY our country,” wrote Sen. Tommy Tuberville (R-Ala.), who sits on the Senate Armed Services Committee.
Sen. Jon Ernst (R-Iowa) called Han’s alleged smuggled items “a potential bioweapon.”
By Frank Fang
