MOSCOW — Liberal Russian politician Boris Nadezhdin was briefly detained by police on Monday, days after being designated a "foreign agent" by Russia's Justice Ministry. Nadezhdin, known for his opposition to the military action in Ukraine and past aspirations to run against President Vladimir Putin, stated on his Telegram channel that he was taken to a police station in Dolgoprudny, a town on Moscow's northern edge where he resides.

He was released several hours later and is scheduled to appear in court later this week. Nadezhdin faces charges related to displaying "extremist symbols," an administrative offense that carries a potential fine or a 15-day jail sentence. According to the independent outlet Zona.media, the charges stem from an online interview conducted in 2023 where Nadezhdin briefly displayed a photograph of the late opposition leader Alexei Navalny. Navalny, who died in February 2024 in an Arctic penal colony, was serving a 19-year sentence on extremism charges that were widely viewed as politically motivated.

Navalny's death was attributed by Russian authorities to natural causes following a walk, though five European countries have jointly stated that he was poisoned by the Kremlin with a rare toxin.

Nadezhdin, a former liberal lawmaker, had openly advocated for a halt to the conflict in Ukraine. He had attempted to run against Putin in the 2024 presidential election but was disqualified after Russia's Supreme Court ruled that a significant number of signatures submitted by his campaign were invalid. Despite the recent "foreign agent" designation, which bars him from running for office, Nadezhdin has stated his intention to run as an independent candidate in parliamentary elections scheduled for September.

Since sending troops into Ukraine in February 2022, Russian authorities have intensified their crackdown on dissent and free speech, targeting rights groups, independent media, civil society organizations, LGBTQ+ activists, and some religious groups. Hundreds have been imprisoned, and thousands have left the country.