Chinese Nationals Arrested in Separate U.S. Smuggling Cases Involving Biological Materials and Weapons for North Korea

This image provided by United States District Court For The Eastern District Of Michigan shows toxic plant pathogens that a Chinese scientist entered the U.S. last year stashed in his backpack, federal authorities said Tuesday, June 3, 2025, as they filed charges against him and a girlfriend who worked in a lab at the University of Michigan

Federal authorities have arrested two Chinese nationals in unrelated but alarming cases involving the illegal import and export of biological materials and military-grade weapons. These cases highlight growing national security concerns about foreign nationals exploiting U.S. research institutions and trade systems for unauthorized activities tied to foreign governments.

In the first case, Chengxuan Han, a citizen of the People’s Republic of China (PRC), was arrested upon arrival at Detroit Metropolitan Airport after allegedly smuggling undeclared biological materials into the United States and making false statements to U.S. Customs and Border Protection (CBP) officers. Han, who is pursuing a Ph.D. at the College of Life Science and Technology at Huazhong University of Science and Technology in Wuhan, reportedly sent four concealed packages to the U.S. in 2024 and 2025. The shipments were addressed to individuals working in a laboratory at the University of Michigan and contained biological samples, which Han later admitted included materials related to roundworms.

According to the FBI, CBP officers conducted a routine inspection of Han’s belongings after her arrival on a J-1 visa. During the screening, Han allegedly lied about the contents of the packages she previously sent and failed to disclose their biological nature. Investigators also found that the contents of her electronic device had been deleted just three days before her arrival. Han later admitted to deleting the information and to providing false statements to officers. U.S. Attorney Jerome F. Gorgon Jr. condemned the incident as part of “an alarming pattern that threatens our security,” emphasizing that such actions should not be funded by American taxpayers.

The second case involves 42-year-old Shenghua Wen, another Chinese national, who pleaded guilty to multiple federal charges related to a weapons smuggling operation orchestrated at the direction of North Korean government officials. Wen, who entered the U.S. on a student visa in 2012 and overstayed after it expired in 2013, was recruited by North Korean operatives to acquire and ship firearms, ammunition, and sensitive technology from the U.S. to North Korea via China.

According to the Department of Justice, Wen first met with North Korean embassy officials in China before moving to the United States. In 2022, North Korean officials contacted Wen via an online platform and instructed him to carry out the arms trafficking operation. Over the following months, Wen purchased military-grade equipment—primarily firearms acquired in Texas—which he transported to California for shipment overseas.

In 2023, Wen bought a firearms business in Houston using funds provided by North Korean contacts. The DOJ confirmed that at least three shipping containers filled with firearms were exported through the Port of Long Beach to China and subsequently rerouted to North Korea. One of those shipments reached Nampo, North Korea, in early 2024.

Wen also planned to ship approximately 60,000 rounds of 9mm ammunition in September 2024. Additionally, he obtained sensitive items including a chemical threat identification device, a broadband signal detection receiver, and components such as a thermal imaging system and a civilian aircraft engine that could be used in reconnaissance missions. Investigators reported that Wen received nearly $2 million in wire transfers from North Korean officials to fund the operation.

Wen admitted in his plea agreement that he knowingly acted as an illegal agent of a foreign government without notifying the U.S. Attorney General, and that he violated the International Emergency Economic Powers Act (IEEPA). He faces up to 30 years in federal prison—20 years for violating IEEPA and 10 years for acting on behalf of a foreign government. His sentencing is scheduled for August 18.

These arrests come amid increased scrutiny of Chinese nationals involved in U.S. academic and commercial sectors, particularly those engaged in scientific and technological research. Officials emphasized the importance of strict compliance with regulations governing the importation of biological specimens and the export of sensitive technologies.

In a related development, officials revealed that two other Chinese researchers were recently charged with attempting to smuggle toxic fungi into the U.S. One was sent back to China at the Detroit airport in 2023, while the other remains in custody pending further legal proceedings.