The short version
- Serhii K becomes the first individual to face trial in Hamburg for the destruction of three Nord Stream gas pipelines in September 2022.
- German authorities classify the act as a war crime involving state-sponsored sabotage, a claim Ukraine denies and which has sparked divergent legal rulings across Europe.
- A second suspect remains in custody after extradition approval from Croatia, while another was released by Polish courts that deemed the alleged actions justified under wartime conditions.
Four years after explosions destroyed three of the four Nord Stream gas pipelines in the Baltic Sea, the first criminal trial related to the incident has begun in Hamburg. Serhii K, identified by German prosecutors as a former Ukrainian military officer, stands accused of plotting with other personnel to sabotage the infrastructure. The charges allege that the group acted under orders from Ukrainian state agencies to disrupt Russia’s ability to finance its war effort through gas revenues. This marks a significant escalation in the legal proceedings surrounding one of the most consequential acts of sabotage in modern European history.
The case presents a delicate diplomatic challenge for Germany, which has positioned itself as one of Ukraine’s closest allies since Moscow launched its full-scale invasion in February 2022. The pipeline attacks occurred seven months after the invasion began, during a period when Western suspicion initially focused on Russia without formal attribution. At the time, Russian President Vladimir Putin blamed the United States and its British allies, an accusation those governments denied. Meanwhile, Berlin had already frozen the multi-billion dollar Nord Stream 2 project shortly before the invasion, and gas flows through Nord Stream 1 had ceased weeks prior to the blasts.
German investigators eventually shifted their focus from state actors in Moscow to a group of deep-sea divers linked to Ukraine. Authorities traced evidence to a yacht named the Andromeda, which was rented in the northern German port of Rostock. Prosecutors stated that samples taken from the vessel contained traces of subsea explosives. This forensic lead allowed German federal prosecutors to argue that the case fell within their territorial jurisdiction and involved undermining internal security, a stance upheld by the German Federal Court of Justice in January 2025.
Serhii K denies the charges against him. He was arrested in August 2025 at a hotel near Rimini on Italy’s Adriatic coast, following a European arrest warrant issued by German federal prosecutors. After weeks of legal battles regarding his extradition, he was transferred to Germany late last year. In court documents, he is identified as Serhii Kuznetsov. Prosecutors allege that in 2022, he led a team comprising professional divers, a boat captain, and an explosives expert to carry out the underwater demolition.
The legal trajectory of other suspects has diverged sharply, illustrating the complex international jurisdictional issues at play. Volodymyr Zhuravlov, another Ukrainian national, successfully challenged Germany’s extradition bid in a Polish court. In October 2025, a Polish judge ordered his release, ruling that the attack on the pipelines was not unlawful and that if Ukraine had organized an armed mission, it would be considered justified, rational, and just under the circumstances of war. This ruling stands in stark contrast to the German legal perspective.
Despite his release from Poland, Zhuravlov’s legal troubles continued when he was arrested in Croatia last August on suspicion of participating in the dives necessary for the sabotage. Croatia recently approved his extradition to Germany, though the timeline for his transfer remains unclear. It is uncertain whether his case will be consolidated with Serhii K’s trial in Hamburg or proceed separately. The disparity in judicial outcomes across European nations underscores the difficulty of applying domestic legal frameworks to acts of alleged state-sponsored sabotage during an active conflict.
In Kyiv, officials have maintained that Ukraine had no involvement in the Nord Stream blasts. Ukrainian President Volodymyr Zelensky has consistently denied any connection to the explosions. Oleksandr Merezhko, who chairs the Foreign Affairs Committee in the Ukrainian parliament, noted that the attacks occurred during wartime and characterized Nord Stream 2 as a tool Russia used to prepare for war. He told reporters that while the German account is one version of events, there is no confirmation from Kyiv to support the allegations of state-directed sabotage.
German officials have attempted to depoliticize the proceedings, emphasizing that the judiciary should handle the case rather than political institutions. Stefan Meister of the German Council on Foreign Relations observed that successive chancellors in Berlin have sought to avoid making a major political story out of the trial. However, prosecutors have framed the charges under Germany’s code of crimes against international law, specifically citing war crimes for attacking civilian objects by military means. This legal framing adds another layer of complexity to an already sensitive diplomatic relationship.
The trial in Hamburg is expected to draw significant attention as it tests the limits of international cooperation in prosecuting alleged war crimes involving allied nations. The outcome could have profound implications for how European countries handle similar cases of infrastructure sabotage during conflicts. As the legal process unfolds, the tension between Germany’s commitment to supporting Ukraine and its obligation to pursue justice under domestic law remains a central theme. The coming months will reveal whether the judicial system can navigate these competing interests without further straining transatlantic and intra-European alliances.
With Serhii K now on trial and other suspects in various stages of extradition or detention, the Nord Stream case has moved from investigative speculation to formal legal adjudication. The proceedings will likely scrutinize the evidence linking Ukrainian military personnel to the explosions, including the forensic findings from the Andromeda yacht. As the court examines the allegations, the broader geopolitical context of the Russia-Ukraine war will remain an inescapable backdrop, influencing both public perception and diplomatic reactions to the trial’s developments.
Sources behind this briefing
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- BBC World↗Germany puts Ukrainian on trial accused of blowing up Nord Stream pipelines
