The White House has said it is seeking information after Russia announced it had arrested a dual US-Russian citizen on treason charges, accusing her of collecting funds for Ukrainian organisations and openly opposing the Russian war in Ukraine. A Russian legal NGO said the woman, named by Russian media as Ksenia Khavana, may stand accused of transferring $51 (£40) to a Ukrainian charity in February 2022, on the day Vladimir Putin launched his invasion of the country. She faces up to 20 years in prison. Russia’s FSB reported on Tuesday that it had detained a 33-year-old woman from Los Angeles who holds dual citizenship. Reports said she had attended the Ural Federal University in Ekaterinburg and later married an American citizen and moved to the US. Photographs from social media showed Khavana smiling, flanked by two American flags, as she holds her US naturalisation documents. Asked about the case, the US national security spokesperson John Kirby reiterated warnings about US citizens travelling to Russia. News of the arrest, which happened in January, came amid a series of reports on Tuesday of a Russian crackdown on perceived threats from abroad. Russia’s state financial monitoring agency added the US senator Lindsey Graham to a database of terrorists and extremists on Tuesday, probably for his criticism of the war in Ukraine. A Russian court also convicted a former adviser to the Russian embassy in France to 18 years in prison on state treason charges, while Russia declared the US Congress-funded Radio Free Europe an “undesirable organisation”, essentially banning its activities in the country. Khavana’s arrest occurred shortly before President Putin confirmed there were backroom talks with the US to negotiate a prisoner exchange, including the jailed Wall Street Journal reporter Evan Gershkovich. Dual citizens are less often considered in such trades. The FSB said in a statement: “Since February 2022, [Khavana] has been proactively collecting funds in the interests of one of the Ukrainian organisations, which were subsequently used to purchase tactical medicine items, equipment, weapons and ammunition by the armed forces of Ukraine. In addition, on the territory of the United States, this citizen has repeatedly participated in public actions in support of the Kyiv regime.” First Dept, an independent Russian legal NGO that focuses on treason cases, said it had information that Khavana had been charged for transferring $51.80 to the Ukrainian charitable fund Razom for Ukraine, which helps fund medical equipment for first responders and other humanitarian causes. The transfer was made on 24 February 2022, according to the group, the day Russia launched its full-scale war against Ukraine. Russia is already holding several US citizens in prison, including Gershkovich, who was arrested last March on espionage charges while on a reporting trip in Ekaterinburg. Gershkovich, who has been held in Moscow’s Lefortovo jail for nearly a year, appeared in court on Tuesday, where a judge extended his pre-trial custody for another two months. Paul Whelan, a former marine who was arrested in 2018 on espionage charges in Moscow is also still in prison, where he says he has felt “abandoned” by the US; and Alsu Kurmasheva, a Russian-American journalist was detained in her native Tatarstan in October on charges of failing to register as a foreign agent, as well as publishing “fake news” about the Russian military. Both Russia and the US have said there are backroom talks about a potential prisoner exchange, but do not appear to have struck a deal yet. Putin compared Gershkovich to Vadim Krasikov, an FSB hitman who was handed a life sentence in Germany for the assassination of Chechen field commander Zelimkhan Khangoshvili in Berlin, when asked about the case by the former Fox News host Tucker Carlson in an interview the Russian president said had a “lack of sharp questions”.