Two Chinese nationals have been accused of smuggling a fungus into the US that officials describe as a "dangerous biological pathogen".
Yunqing Jian, 33, and Zunyong Liu, 34, have been charged with conspiracy, smuggling goods, false statements, and visa fraud, the US Attorney's Office for the Eastern District of Michigan announced on Tuesday.
The complaint alleges Mr Liu tried to smuggle the fungus through Detroit airport so he could study it at a University of Michigan laboratory where his girlfriend, Ms Jian, worked.
The fungus called Fusarium graminearum can cause a disease in wheat, barley, maize and rice that can wipe out crops and lead to vomiting and liver damage if it gets into food.