The 47-year-old, Krzysztof Flaczek, arrived in Ukraine in September 2024, where he began participating in combat operations after receiving training, the Prosecutor General's Office said, as cited by the Reuters news agency.
Russia said he received financial compensation for fighting for Ukraine. He was captured by Russian forces in November 2024.
"Taking into account the position of the state prosecutor, the court sentenced the militant to 13 years of imprisonment to be served in a maximum-security penal colony," prosecutors said.
Flaczek was tried by a court in Russian-controlled Luhansk, one of four Ukrainian regions that Moscow claimed as its own in 2022 in a move Kyiv and the West have rejected as an illegal land grab, Reuters reported.
Russian courts have sentenced several Western Europeans for fighting for Ukraine, including two Britons, according to Reuters.
(gs)
Source: Reuters, PAP, themoscowtimes.com