The Nord Stream explosions and Germany's case against Ukrainian suspects

Responsibility for the explosions was disputed. Russia alleged US involvement and sought a UN investigation in February 2023.^[10] The Security Council did not adopt the proposal the following month. The US deputy ambassador said the Swedish, Danish and German investigations made a UN inquiry unnecessary.^[11] Ukraine denied involvement in the attack.^[12]

Media reports described possible Ukrainian connections. In March 2023, The New York Times reported that intelligence reviewed by US officials suggested a pro-Ukrainian group had carried out the attack. The officials said there was no evidence of involvement by Ukrainian President Volodymyr Zelenskyy or his government.^[13] Sweden's lead prosecutor said in April that a state actor was the most likely culprit.^[14] In June, The Washington Post reported that a European intelligence agency had alerted the CIA to a Ukrainian plan before the explosions,^[15] and further reporting said the CIA had warned Ukraine against an attack.^[16] That November, the Post reported that Ukrainian military officer Roman Chervinsky had coordinated the operation.^[17]

Sweden closed its investigation in February 2024, citing a lack of jurisdiction.^[3] Denmark closed its inquiry later that month, concluding that sabotage had occurred but that there were insufficient grounds for a criminal case.^[4]

Germany's investigation continued. Prosecutors said in March 2023 that they had searched a vessel suspected of carrying explosives.^[12] German media reported in August 2024 that an arrest warrant had been issued for a Ukrainian diving instructor identified as Volodymyr Z., whose last known address was in Poland.^[18] Italian police arrested a Ukrainian identified as Serhii K. in August 2025 on suspicion of coordinating the attack.^[19] In July 2026, German prosecutors charged former Ukrainian army officer Serhii Kuznietsov. They accused him of leading the diving team and acting on orders from state authorities in Ukraine.^[5]

A Ukrainian suspect was arrested in Croatia in August 2026 on a European warrant. German prosecutors accused him of belonging to the group that planted the explosives.^[6] Croatian state television reported in September that a court had approved his extradition to Germany. His lawyers said they would appeal.^[7] On October 27, a German court rejected a defense request to end the trial of a former Ukrainian army officer accused of damaging the pipelines.^[20]