"He was held captive by the occupiers for two years and eight months and tortured to death. In the latest prisoner exchange, his body was returned to Ukraine, writes the region's governor Ivan Fedorov on Telegram.
Russia occupied large parts of Zaporizhzhya shortly after the war of aggression began in February 2022. The city of Dniprorudne with nearly 18,000 inhabitants, where Yevhen Matveiev was mayor, was one of the areas that fell.
Several high-ranking politicians, including Ukraine's former Foreign Minister Dmytro Kuleba and EU Council President Charles Michel, have demanded clarity on the mayor's disappearance and his release.
Fedorov describes Matveiev as a "true patriot".
"During the occupation, he never left the city or the people. He did everything to ensure the community's survival", writes the governor.
Russia has not commented on the case.