On 17 February 2021, he was detained and taken into custody on the same day on charges of organising activities of a terrorist organisation due to his alleged involvement with the Islamist party Hizb ut-Tahrir, which has no connection with terrorism. In May 2022, Eyupov's cellmate told his lawyer that he was showing signs of a stroke or microstroke - his left leg and arm were not functioning properly and he was unable to move around his cell. On 19 July 2022, he was sentenced to 17 years in a strict regime penal colony.