On October 14, 2026, the first criminal trial over the 2022 sabotage of the Nord Stream gas pipelines opened at the Hamburg Higher Regional Court. In the dock is Serhii K., a former Ukrainian army officer accused of war crimes, causing an explosion and disrupting public services. He denies any involvement, and the question of who ultimately ordered the operation remains unresolved.
The court has scheduled 16 hearing dates through December 17, 2026, with further dates planned for January and February 2027.
What the seismologists recorded
On September 26, 2022, two underwater explosions struck the pipelines near the Danish island of Bornholm. Seismometers on Bornholm and across the region recorded two distinct events, described by the Geological Survey of Denmark as characteristic of explosions rather than natural events. Björn Lund of the Swedish National Seismic Network said the blasts were "at least equivalent to 100 kilograms of dynamite."
Three of the four pipeline strings were damaged. The pipelines were not operational at the time.
How investigators closed in
German police and prosecutors built the case largely from ordinary, fragmentary records. According to German public broadcaster ARD, the breakthrough came from photographs taken by tourists at Baltic Sea ports, which showed vehicles used to move the suspected sabotage team to and from the coast.
A second thread came from a German speed camera. A grainy black-and-white image captured the face of a Ukrainian deep-sea diver, whom police identified using commercial facial-recognition software, quickly leading to social media accounts and links to other suspects, according to reporting carried by Ukrainska Pravda from The Wall Street Journal.
Border data added more. Although the group travelled on forged passports, a scan of one document stored after a Polish border check produced an image investigators considered an unambiguous match for Serhii K. — clear enough, the indictment reportedly states, to exclude an identical twin.
Digital evidence also featured prominently. Prosecutors say Serhii K.'s seized phone contained maritime charts and technical files on the pipelines, along with search histories covering water depths, coordinates and economic zones. His Garmin sports watch, otherwise in constant daily use, recorded no data during the weeks the team is alleged to have sailed the Baltic.
The yacht and the alleged operation
Prosecutors allege that Serhii K. led a team of divers, a skipper and an explosives expert into Germany on forged Ukrainian passports in September 2022. The group chartered the 15-metre sailing yacht Andromeda in Rostock-Warnemünde for roughly €12,000, using it to transport military-grade explosives to the pipeline site near Bornholm.
The indictment alleges six explosive charges were attached to three of the four pipelines with timers, detonating four days later.
Two arrests, two different paths
Serhii K. was arrested in Italy in August 2025 and extradited to Germany in November 2025 after multiple rounds of Italian judicial review. His trial is the first to emerge from the investigation.
A second suspect, Vladimir Z., a trained scuba diver, was arrested in the Croatian town of Pula in August 2026 under a European arrest warrant. A Croatian court approved his extradition in September, though his lawyer said the ruling would be appealed, leaving the final outcome open.
Allegations of state direction
German federal prosecutors allege that Serhii K. and six accomplices acted "on the orders of state authorities in Ukraine," with the aim of permanently halting gas supplies and preventing Russia from using gas revenue to finance its war effort.
An early assessment by Germany's BKA federal police, reported by Der Spiegel, described the blasts as "a targeted act of sabotage" and said state-actor involvement appeared probable given the operation's complexity. That assessment was made before suspects were identified.
Reporting by The Wall Street Journal, carried by Ukrainska Pravda, said German investigators had established that the group acted under the direction of Valerii Zaluzhnyi, then commander-in-chief of the Ukrainian Armed Forces. Zaluzhnyi has denied this, and Ukrainian President Volodymyr Zelenskyy has said Ukraine had nothing to do with the attack.
A limited role for the pipeline operators
The Hamburg court separately denied Nord Stream AG and Nord Stream 2 AG, both controlled by Russia's Gazprom, the right to join the trial as co-plaintiffs. The court found the companies had suffered losses but ruled they were not existentially threatened, and that the criminal trial was not the venue for pursuing economic claims or a broader political reckoning. The companies may reapply if accusations are raised against them during the hearings.
What is confirmed, unknown and awaited
Confirmed: the explosions and their seismic signature; the charges against Serhii K.; the two arrests; the trial schedule in Hamburg; and prosecutors' allegation of Ukrainian state direction.
Unknown: whether the court will accept the prosecution's account of the operation; whether Vladimir Z. will ultimately be extradited; and whether any evidence of a chain of command will be tested in court.
Awaited: the trial's outcome, expected to extend into February 2027, and any ruling on the defence arguments around state orders, combatant privilege and immunity, which Germany's Federal Court of Justice has so far rejected at the arrest stage.