Serhii K, a former Ukrainian Special Forces soldier, is accused by German police of commanding the explosions in September 2022 that ruptured the Nord Stream pipelines. He faces charges of causing an explosion and a war crime for allegedly attacking civilian infrastructure on behalf of "state agencies of Ukraine." Both Serhii K and Ukraine deny any involvement. He was extradited from Italy after being identified as a key suspect in August 2025. Another suspect, Volodymyr Zhuravlyov, is currently fighting extradition from Croatia.