Prosecutors to drop charges against Russian-born Harvard scientist accused of smuggling frog embryos

Federal prosecutors in Boston have moved to drop criminal charges against Kseniia Petrova, a Russian-born biomedical researcher at Harvard Medical School accused of bringing undeclared frog embryos into the US. The move came after a judge ruled she had shown enough evidence of possible selective prosecution to access government records, supporting her claim that she was targeted for challenging immigration proceedings.

Immigration authorities detained Petrova at Boston airport in February 2025 after revoking her visa when she returned from France. Prosecutors charged her in May with smuggling and making a false statement, alleging her checked bag contained embryos that should have been declared; she pleaded not guilty and was released on bail in June. Petrova said her boss had asked her to bring the samples for experiments, and a Vermont judge ruled in April that her visa had been unlawfully cancelled.