A Chinese research student accused of smuggling biological materials into the U.S. for work at a University of Michigan laboratory has been sentenced to time served and will return to China. 

On Wednesday, Chengxuan Han, 28, of the People's Republic of China, was sentenced by U.S. District Judge Matthew Leitman.

In August, Han, who is a doctoral student at the College of Life Science and Technology in the Huazhong University of Science and Technology in Wuhan, China, pleaded no contest to three smuggling charges and to making false statements to U.S. Customs and Border Protection officers. 

According to federal investigators, Han sent four packages to the U.S. from China containing concealed biological material in 2024 and 2025. Those packages were allegedly addressed to people associated with a University of Michigan laboratory. 

Han was stopped by U.S. Customs and Border Protection officers at Detroit Metropolitan Airport after arriving on a J1 visa on June 8. While officers inspected Han, she reportedly lied to authorities about the packages and the biological materials she had allegedly previously sent to the U.S.

During an interview with the FBI, agents say Han admitted to sending the packages, saying the packages contained biological material related to roundworms. Han also allegedly admitted to lying to officers during her inspection. 

Han is one of three Chinese nationals accused of smuggling biological material into Michigan. In June, Yunqing Jian, 33, a postdoctoral fellow at the Ann Arbor school, and her boyfriend, Zunyong Liu, 34, were charged with conspiracy, smuggling goods into the U.S., false statements and visa fraud.

Before Wednesday's sentencing, federal prosecutors had asked that Han, who has been jailed since June, be sentenced to six months in a federal prison.

Han's defense team pushed back and asked for her immediate release and return to her native country, citing a lack of a past criminal history, and said she was a talented scientist who made a mistake. 

Han spoke for nearly five minutes Wednesday and discussed how the incident has damaged her personal and professional life before asking the judge to consider her attorney's pleas. 

Immediately after Wednesday's hearing, Han's attorneys said they were happy with the outcome and hoped to have her on a flight home by the end of the week. 

The FBI, ICE, Homeland Security Investigations and U.S. Customs and Border Protection investigated Han's case.