December 17, 2018, he was detained in Donetsk by officers of the Ministry of State Security of the self-proclaimed DPR. He spent two months in the departmental detention centre. According to Marchenko, he was tortured in order to get information about people from his phone's address book. February 18, 2019, Marchenko was taken to Krasnodar, where he claimed to be a witness in the criminal case. The next day, the court arrested Marchenko for 10 days under the article of the Code of Administrative Offences for disobedience to the lawful demand of a law enforcement representative. Upon leaving the special reception centre, Marchenko was arrested for 15 days and awarded a fine of two thousand rubles under the articles on disobedience to the lawful demands of law enforcement officers and on illegal labour activity of a foreign citizen on the territory of the Russian Federation without a patent. Marchenko said that representatives of the FSB Department of the Krasnodar region came to the detention centre and took him away from there. At the end of the arrest term, Marchenko was transferred to the Centre for Temporary Detention of Foreign Citizens. May 1st, 2019, the court placed him on remand in custody in the case of preparing to smuggle military equipment.

November 26, 2020, he was sentenced to ten years in a strict regime penal colony.

In February 2024, it became known that Marchenko would be transferred from the colony to prison for three years, since he violated the order of serving his sentence 18 times.

You can read more about politically persecuted people in the Telegram channel OVD-Info LIVE and our politically motivated criminal prosecutions in Russia database