Sergei Mamaev is a political prisoner
An activist from Yoshkar-Ola has been sentenced to two years and eight months’ imprisonment on a charge of involvement in the ‘Navalny Headquarters’
The ‘Political Prisoners. Memorial’ human rights project, in accordance with international standards, considers Sergei Mamaev a political prisoner. Mamaev was convicted on a charge of ‘participation in the activities of an extremist organisation’ for posts he published in support of Aleksei Navalny and for laying flowers in his memory. Mamaev’s criminal prosecution and conviction violated his rights to freedom of expression, freedom of association and fair trial. We demand the release of Sergei Mamaev and that all criminal charges against him be dropped.
Who is Sergei Mamaev and what are the charges against him?
Sergei Mamaev, aged 45, is a civic activist from Yoshkar-Ola. He had no connection with Aleksei Navalny’s organisations, but after the politician’s arrest in 2021 he repeatedly expressed support for him.
On Aleksei Navalny’s birthday, 4 June 2023, Mamaev posted on the VK social media platform a photograph of himself wearing a T-shirt with the words ‘Free Navalny.’ The following year, after Navalny’s death, he posted a photograph of flowers he had laid at the Memorial to Victims of Repression in memory of Navalny. On 17 March 2024, the day of the ‘Noon Against Putin’ protest, Mamaev published a photograph of a ballot paper with the word Navalny written on it, and on the 40th day after the politician’s death, he posted another photograph of Navalny. These publications, along with two links to Navalny’s channel, became grounds for charging Mamaev with involvement in the ‘Navalny Headquarters.’
On 22 July 2025, Sergei Mamaev was detained. That same day, security officers searched his apartment and his dacha, and he was taken for interrogation to the Investigative Committee. He was then remanded in custody on a charge of ‘participation in the activities of an extremist organisation’ (Article 282.2, Part 2, of the Criminal Code of the Russian Federation).
On 16 February 2026 Mamaev was sentenced to 2 years and 8 months of imprisonment in a general-regime penal colony.
Why do we consider Sergei Mamaev a political prisoner?
An analysis of available materials that formed the basis for the decision by the Moscow City Court to designate Aleksei Navalny’s organisations as extremist shows that the ruling was politically motivated and unlawful.
Firstly, no evidence of actual extremist activity by these organisations was presented. Administrative and criminal cases against individual employees do not constitute such evidence.
Secondly, regular official inspections of the organisations revealed no extremism in their activities, yet the court nonetheless treated the results of these inspections as confirmation of alleged extremist activity.
For these reasons, Mamaev’s criminal prosecution is based on an unlawful decision by Moscow City Court and is politically motivated.
Furthermore, publishing social media posts in support of, or in memory of, a politician cannot be regarded as participation in any organisation. Such actions are not crimes. In any case, social media posts cannot lead to the resumption of the activities of the ‘Navalny Headquarters,’ which were unlawfully closed down by the Russian authorities.
A detailed description of Sergei Mamaev’s case and of our position is available on our website.
How can you help?
You can write to Sergei Mamaev at the following address:
RU:
425200, Республика Марий Эл, пгт. Медведево, ул. Медведево, д. 1, ФКУ ИК-3 УФСИН России по Республике Марий Эл, Мамаев Сергей Олегович, 1980 г. р.
EN: Sergei Olegovich Mamaev (born 1980), Penal Colony No. 3, Federal Penitentiary Service of Russia for the Republic of Mari El, 1 Ulitsa Medvedevo, Medvedevo settlement, Republic of Mari El, 425200, Russia
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