US moves to drop frog embryo smuggling charges against Harvard scientist

US prosecutors have moved to drop criminal charges against Kseniia Petrova, a Russian-born Harvard scientist accused of smuggling frog embryos into the United States. The case is significant because Petrova argued that she was selectively and vindictively prosecuted after challenging immigration proceedings against her.

Prosecutors said they considered her claims meritless but that continuing the case after a judge ordered access to government records would divert resources from more substantial federal interests. Petrova was detained at Boston airport in February 2025 after her visa was revoked, then charged with smuggling and making a false statement over embryos in her luggage; she pleaded not guilty and said her boss had asked her to bring the samples for research. A judge ruled in April that her visa had been unlawfully cancelled, and last month found she had presented enough evidence to seek records supporting her selective-prosecution claim.