A US-Russian dual national working for Radio Free Europe has been detained in Russia and charged with failing to register as a foreign agent, the US-funded news organization reported Wednesday.

Alsu Kurmasheva is currently employed as a journalist and editor for the Tatar-Bashkir service of Radio Free Europe/ Radio Liberty (RFE/RL) and is based in Prague.

According to her employer, Kurmasheva was detained on June 2 in the city of Kazan in Russia while waiting for a return flight to the Czech Republic. She had arrived in Russia on May 20 due to an urgent family matter, RFE/RL said.

RFE/RL said Kazan airport employees initially confiscated both of her passports and soon after she was fined for failing to register her American passport with the Russian authorities. Kurmasheva was waiting for the return of her passports when new charges were announced on October 18, RFE/RL said, adding that she was accused of refusing to register as a foreign agent.

The RFE/RL acting president Jeffrey Gedmin issued a statement Wednesday calling for Kurmasheva's immediate release.

According to RFE/RL, Kurmasheva is an accomplished journalist who has been writing about the life of ethnic minorities in Russia's Tatarstan and Bashkortostan regions for many years. Kurmasheva reports on civil initiatives aimed at protecting and preserving the Tatar language and culture in the face of growing pressure from the Russian authorities, RFE/RL said.

Russia expanded its law on "foreign agents" in 2022 following its full-scale invasion of Ukraine, signifying an intensifying crackdown on free speech and opposition under President Vladimir Putin. Now, not only individuals or organizations receiving funding from abroad are regarded as foreign agents but also anyone who has "received support and (or) is under foreign influence."

CNN has contacted the US State Department and the US embassy in Moscow for comment.

In March 2023, Wall Street Journal reporter Evan Gershkovich was arrested on a work trip in Russia and charged with espionage — accusations that he and his employer vehemently denied. He's the first US journalist to be accused of spying by Moscow since 1986, when US reporter Nick Daniloff was detained on a similar charge. If convicted, Gershkovich faces up to 20 years in prison.