Kseniia Petrova

Kseniia Petrova is a Russian biomedical researcher who was detained by the United States Immigration and Customs Enforcement after her travel visa was revoked when returning to the US from a holiday in France in February 2025.

Upon her return to the US, she imported frog embryo samples with her under request from her work at Harvard Medical School; these samples were legal to import, but she had incorrectly filled in the customs declaration form; instead of the usual punishment for this error of up to a $500 fine, her J-1 visa was revoked by an official at Logan International Airport. After stating she was afraid of political persecution if she were to be deported to Russia, she was taken to a detention facility in Vermont and then to Richwood Correctional Center in Monroe, Louisiana. Her colleagues campaigned for her release in the US, noting her rare skill in both genome biology and computing which had allowed her to help their investigation of the renewal of cells to mitigate the damage of aging.

After four months in detention, on June 12, 2025, Kseniia was freed on bail. In 2021, Petrova graduated from the Russian Physics and Technology Institute.

Career 2021–23: Rosneft project in Moscow and anti-war protest Petrova was quickly recruited by prominent Rutgers University molecular biologist Dr Konstantin Severinov after graduation for a genome-sequencing project in Moscow. joining protests against the invasion in Moscow. She was arrested for this on March 2, 2022, and was charged with an administrative violation, fined about $200 and released. Seeing that the news sources she relied on for objective information "closed immediately" and fearing the Russian border would also close, she fled the country two days later.

Release and proceedings

After a hearing before a federal judge in Boston, Petrova was released on bail on June 12, 2025. A probable cause hearing was held on June 19, during which the veracity of her statements and the scope of the cited law were debated. On June 25, 2025, a federal grand jury indicted Petrova on charges of making false statements to customs officials.

In April 2026, Judge Christina C. Reiss ruled that the CBP's actions had been "arbitrary and capricious", and that they had not had the authority to cancel Petrova's visa.

Responses Her coworker Cora Anderson shared the news of her detention on Facebook on 26 March, and set up a GoFundMe campaign for her application for a new visa despite her inability to work while doing so. Lawyer Gregory Romanovsky took on her asylum case, asking for Petrova's parole twice and being denied this both times by ICE, which has stated that she is a flight risk and a threat to US security. Harvard University commented little on her detention, though stated it was "engaged with Ms. Petrova's attorney on this matter." Marina Sakharov-Liberman, granddaughter of the Soviet physicist and dissident Andrei Sakharov, called it "extraordinary" that Harvard had not more publicly protested her detention. Petrova's colleagues expressed worry that they may not see her again if she were deported to Russia, with many of her colleagues who were on temporary visas being reluctant to sign letters of support due to a risk to themselves. Prominent figures in Russia's political opposition have warned against delivering Petrova to Russia, whereas other young, educated Russians who fled the country after its invasion of Ukraine are watching the case as an example.

Petrova's attorney Romanovsky has said that Customs and Border Protection had overreached its authority by canceling her visa, which required them to identify grounds for excluding her, stating that "there are many, many grounds of inadmissibility, but violating a customs rule is certainly not one of them". This has been echoed by Stanford Law School professor Lucas Guttentag, who has said that "the government itself created the alleged improper immigration status that is now the basis for her detention."