A Russian-born scientist and Harvard University cancer researcher accused of smuggling frog embryos into the United States has been released following four months in federal custody Thursday. 

Kseniia Petrova, 30, was arrested in February after returning from a vacation in France, where she had obtained a package of superfine sections of frog embryos from a laboratory for research. Upon arriving at Boston Logan International Airport, Petrova was questioned by U.S. Customs and Border Protection regarding the materials. 

“I just want to thank everybody,” Petrova said on the steps of the federal courthouse in Boston following her release. “A lot of people started contacting me and sending me letters, and it was a huge support without which I won’t be able to survive.”

Kseniia Petrova, a Russian-born scientist and research associate at Harvard University, leaves the John Joseph Moakley United States Courthouse after she was released from U.S. federal custody while awaiting trial in a criminal case in Boston on June 12, 2025. (REUTERS/Reba Saldanha   )

Petrova’s colleagues have previously testified on her behalf, telling the court she is conducting valuable research that aids in searching for a cure for cancer. 

Greg Romanovsky, the immigration attorney representing Petrova, said his client has not “decided whether she wants to stay in the United States yet.” 

“She has offers from different countries around the world, countries that are eager to support the important research that she’s doing,” he said. “She’s weighing her options at the moment, and she’s very grateful to be out.” 

Romanovsky did not immediately respond to Fox News Digital’s request for comment. 

Under the conditions of her release, Petrova must report any contact with law enforcement – including ICE – to her supervising officer within 24 hours, according to court documents obtained by Fox News Digital. 

Petrova is scheduled to return to court next week for a probable cause hearing regarding the smuggling charge. 

The Associated Press contributed to this report.