FBI arrests 3rd Chinese national in US for smuggling biological materials

A Chinese PhD student has been detained for allegedly smuggling roundworm-linked biological materials into the US. This comes amid a broader probe into unauthorised CCP-linked bio-research

A third Chinese national has been arrested in connection with a widening investigation into the unauthorised smuggling of biological materials into the United States, FBI Director Kash Patel said on Tuesday.

 

In a post on X, Patel confirmed that Chengxuan Han, a PhD student from Wuhan, China, was detained by agents from the FBI Detroit at Detroit Metropolitan Airport on June 8. Han stands accused of sending four packages containing biological materials related to roundworms to individuals affiliated with a laboratory at the University of Michigan.

 

Han allegedly made false statements to federal officers about the packages and had erased her electronic device shortly before arriving in the US. In a subsequent interview with agents from the FBI and Immigration and Customs Enforcement’s Homeland Security Investigations (ICE HSI), she admitted to both sending the shipments and lying about their contents.

 

 

“She is the third PRC-connected individual charged on similar allegations in recent days,” Patel said, framing the arrest as part of a broader national security crackdown on covert biological research linked to the Chinese Communist Party (CCP). “The CCP is working relentlessly to undermine America’s research institutions,” he said.

Yesterday, @FBIDetroit arrested a second Chinese national on charges of smuggling biological materials into the U.S. and lying to federal agents.  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

— FBI Director Kash Patel (@FBIDirectorKash) June 9, 2025

 

Prior FBI arrests and agroterrorism concerns

This arrest follows the recent detention of two other Chinese nationals, Yunqing Jian, a Chinese researcher formerly employed at the University of Michigan, and her partner Zunyong Liu, a researcher at a Chinese institution. The pair has been charged with smuggling a dangerous agricultural pathogen, Fusarium graminearum, into the US without authorisation.

 

Investigators allege that Jian brought the fungus into the country covertly, continued her research in violation of US biosecurity protocols, and had previously received funding from the Chinese government. Liu is accused of helping smuggle the pathogen through Detroit airport and initially denying involvement before ultimately admitting to the charges.

 

The University of Michigan has stated that it had no knowledge of the unauthorised shipments and is cooperating fully with federal authorities in their ongoing investigations.

 

Is the ‘smuggled’ fungus dangerous?

The fungus, which causes Fusarium head blight, poses a significant threat to cereal crops and can produce toxins harmful to humans and livestock. While federal prosecutors have labelled the case as an example of ‘agroterrorism’, some experts argue that the fungus is already present in the US and is manageable through existing agricultural practices.

 

While US authorities have not confirmed whether the smuggled roundworm materials or agricultural fungus posed an immediate public health threat, they emphasised the broader biosecurity and national security risks associated with such unauthorised imports. 

 

US crackdown on Chinese student visa

The series of arrests comes amid heightened scrutiny of Chinese nationals engaged in research within the US, particularly in sensitive sectors such as biotechnology, artificial intelligence, and aerospace. The US government has announced stricter visa regulations for students and researchers from China and Hong Kong.