On Wednesday a German court in Hamburg opened a trial against Serhii K, a Ukrainian national identified in court documents as Serhii Kuznetsov. Prosecutors accuse him of planning and executing the September 2022 explosions that ruptured three of the four Nord Stream pipelines in the Baltic Sea.
Background to the sabotage
On 26 September 2022, explosives destroyed three of the four Nord Stream gas pipelines off the Danish island of Bornholm. The attacks occurred weeks after Russia had halted gas deliveries through Nord Stream 1 and before the unfinished Nord Stream 2 could be commissioned. Initial investigations by Sweden, Denmark and Germany did not assign blame, and Russian President Vladimir Putin later accused the United Kingdom and the United States of involvement.
Legal proceedings in Germany
German prosecutors allege that Serhii Kuznetsov, then a serving officer in the Ukrainian army, led a team of professional divers, a boat captain and an explosives expert who rented the yacht Andromeda in Rostock. They claim traces of subsea explosives were found on the vessel. In January 2025 the German Federal Court of Justice confirmed that the case falls under German territorial jurisdiction and that the alleged acts constitute a war crime—"an attack by military means against civilian objects" under Germany’s code of crimes against international law.
Serhii Kuznetsov denies all charges. A second Ukrainian suspect, currently detained in Croatia, is fighting extradition and may be added to the Hamburg trial.
Political context
Ukraine’s President Volodymyr Zelensky has repeatedly stated that Ukraine had "nothing to do with" the Nord Stream blasts. Nevertheless, the indictment alleges that the sabotage was carried out "by order of Ukrainian state agencies." Ukrainian MP Oleksandr Merezhko, chair of the Foreign Affairs Committee, described the pipelines as a tool for Russia and said the German version is only one of several narratives. German analyst Stefan Meister stressed that German authorities are trying to keep the case out of the political spotlight, emphasizing the role of the judiciary.
Other related cases
- Volodymyr Zhuravlov – another Ukrainian man who was released by a Polish court in October 2025 after the judge ruled the alleged attack was not unlawful. He was later arrested in Croatia and awaits extradition.
- Extradition saga – Serhii Kuznetsov was arrested in Italy in August 2025 after checking into a hotel near Rimini, fought extradition for several weeks, and was transferred to Germany late that year.
Outlook
The trial is expected to last several weeks, with prosecutors seeking convictions for sabotage and war crimes. Observers note that the outcome could affect German‑Ukrainian relations, but both governments have signalled a desire to keep diplomatic ties intact despite the legal dispute.