Chinese Scientists Cleared of Worm Smuggling Charges After Government Intervention

Charges against three University of Michigan researchers were dropped after Chinese officials negotiated with the U.S. Justice Department.

Published on Feb. 25, 2026

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Three Chinese scientists at the University of Michigan who were accused of helping a colleague smuggle biological materials into the U.S. had the charges against them suddenly dropped after the Chinese government intervened. The materials turned out to be mostly tiny, transparent worms that were not dangerous, though U.S. officials had initially hailed the arrests as a victory for national security. Defense lawyers said the dismissal came as a surprise after they had been working toward a plea deal, and they were told the Chinese Consulate in Chicago had negotiated with the U.S. Justice Department.

Why it matters

The case highlights tensions between the U.S. and China over scientific research and the flow of information and materials across borders. It raises questions about how the U.S. government handles investigations and prosecutions of foreign nationals engaged in academic research, and whether political considerations can influence the legal process.

The details

Xu Bai, Fengfan Zhang, and Zhiyong Zhang were charged with conspiring to help another scientist, Chengxuan Han, who shipped packages to them from China before she arrived in 2025 for temporary lab research at the University of Michigan. The packages contained mostly harmless worms used for studying chemical reactions and light sensitivity. After being jailed for over three months, the charges against the three men were suddenly dismissed on February 5 at the request of the Justice Department, and they were able to return to China.

  • In September 2025, Chengxuan Han pleaded no contest to smuggling and making false statements and was deported to China after three months in jail.
  • In a separate case, Yunqing Jian, another temporary researcher at a campus lab, pleaded guilty to similar charges involving a common plant fungus and was deported after five months in custody.
  • On February 5, 2026, the charges against Xu Bai, Fengfan Zhang, and Zhiyong Zhang were dismissed at the request of the Justice Department.

The players

Xu Bai

One of three Chinese scientists at the University of Michigan who were charged with conspiring to help a colleague smuggle biological materials into the U.S.

Fengfan Zhang

One of three Chinese scientists at the University of Michigan who were charged with conspiring to help a colleague smuggle biological materials into the U.S.

Zhiyong Zhang

One of three Chinese scientists at the University of Michigan who were charged with conspiring to help a colleague smuggle biological materials into the U.S. and making false statements to authorities.

Chengxuan Han

A scientist who shipped packages containing mostly harmless worms from China to the three University of Michigan researchers before arriving in the U.S. for temporary lab research. She pleaded no contest to smuggling and making false statements and was deported to China.

Yunqing Jian

Another temporary researcher at a campus lab who pleaded guilty to charges involving a common plant fungus and was deported after five months in custody.

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What they’re saying

“The dismissal came as a pleasant surprise. We don't know the details. What we were told was there was some kind of intervention by the Chinese Consulate in Chicago.”

— John Minock, Defense lawyer

“These were kids studying for their Ph.D.s. The last thing you want to do is destroy their careers. … Was it the proper thing to do? Absolutely.”

— Ray Cassar, Defense lawyer

“There was no intention of doing anything nefarious. The worms have been consistently used for studying chemical reactions, light sensitivity.”

— Ray Cassar, Defense lawyer

What’s next

The U.S. Attorney's Office in Detroit said it would not comment on China's role or the government's retreat in the case.

The takeaway

This case highlights the complex geopolitical tensions and legal issues surrounding scientific research and cross-border exchanges, as well as questions about how the U.S. government handles investigations and prosecutions of foreign nationals engaged in academic work.