Sergei was arrested and convicted of insulting officials. According to investigators, on April 2, 2021, he sent emails to the Vitebsk Regional Prosecutor's Office and the district executive committee containing offensive statements directed at the deputy prosecutor and the first deputy chairman of the district executive committee. An expert examination found the wording of the emails to be abusive and aimed at creating a negative image of government officials.
In addition, he was charged with violating weapons storage regulations and illegal possession of an explosive substance – black powder suitable for detonation.
According to human rights activists, he was released in the summer of 2024, having fully served his sentence imposed by the court.
