A Ukrainian ex-military officer identified under German privacy rules as Serhii K. appeared before the Hanseatic Higher Regional Court in Hamburg on Wednesday, becoming the first person to stand trial over the September 2022 sabotage of the Nord Stream gas pipelines in the Baltic Sea. The German Federal Prosecutor's Office accuses him of co-organising the covert operation and has charged him as a co-perpetrator of a war crime, alleging that attacking civilian infrastructure and causing the explosions that destroyed the pipelines meets that threshold.
Prosecutors allege that Serhii K. — identified elsewhere as Serhiy Kuznetsov — led a group of Ukrainian agents, including divers and an explosives expert, who were operating 'on behalf of state authorities in Ukraine' [Source: RFE/RL]. He is said to have entered Germany through Poland roughly three weeks before the attack using a forged Ukrainian passport. The group allegedly hired a sailboat in Rostock, departed on 6 September 2022, and sailed to an area near the Danish island of Bornholm, where they rigged military-grade explosives with timers to the sea floor before returning to port on 23 September. Serhii K. was arrested under an international warrant in Italy in 2025. He has denied any involvement in the blasts, and his German lawyer, Jes Meyer-Lohkamp, said prosecutors have not provided any direct, conclusive evidence of his client's involvement [Source: RFE/RL]. Kyiv has strictly denied any state involvement in the attack.
German prosecutors have identified seven Ukrainian suspects in total, but only Serhii K. is currently in the dock. Croatian authorities have separately arrested another man, identified as Vladimir Z., whom prosecutors believe was one of the divers. The Hamburg trial is expected to run into February 2027.
On 26 September 2022, Swedish seismologists detected several blasts approximately 17 hours apart that ruptured three of the four concrete-coated steel pipelines, sending large plumes of methane into the atmosphere. The Nord Stream system — a twin pipeline network with a combined annual transport capacity of around 55 billion cubic metres of gas and a total investment of 7.4 billion euros — was operated by Nord Stream AG, a Zug, Switzerland-based consortium in which Gazprom holds a 51% stake, with Wintershall Dea and PEG Infrastruktur AG/E.ON each holding 15.5%, and N.V. Nederlandse Gasunie and ENGIE each holding 9%. Nord Stream 1 had begun operations in November 2011 and supplied two-thirds of Germany's total gas imports in 2021. Western officials initially attributed the blasts to Russia, though no government has been formally charged. The destruction of the pipelines marked the end of Germany's longstanding dependence on Russian natural gas, a shift that had already been under way after Moscow curtailed supplies following Berlin's support for European sanctions. In November 2022, Germany fully nationalised Gazprom Germania, a wholly owned Gazprom subsidiary now known as Securing Energy for Europe.
The trial carries political resonance in Germany, where the far-right Alternative for Germany party, which has led opinion polls for more than a year, has called for an end to military aid for Ukraine and a restoration of energy ties with Moscow [Source: Reuters].
Sources: Reuters, RFE/RL, Nord Stream AG, Brookings