A Ukrainian former military officer is to go on trial in Germany on Wednesday, accused of organising the secret operation that blew up the Nord Stream pipelines in September 2022, severing western Europe from the biggest source of Russian natural gas.
The suspect, identified under German privacy rules only as Serhii K., is accused of leading a group of Ukrainian agents, including divers and an explosives expert, to mount one of the biggest infrastructure sabotage operations of modern times.
The case will provide the first opportunity for a public hearing of evidence gathered during a years-long investigation, which has been diplomatically and politically awkward for a German government that remains staunchly supportive of Ukraine despite the investigative trail linking Kyiv to the crime.
Prosecutors have alleged that Serhii K., who was arrested under an international warrant in Italy last year, worked with other members of the military to plan the clandestine operation on behalf of unidentified Ukrainian state entities.
Serhii K. has denied any involvement in the blasts that ruptured the 1,200km-long Baltic Sea pipeline.
The government in Kyiv has also denied any involvement, a sensitive point in its relations with Germany, Ukraine's largest European supplier of military aid. The Russian government said it expected a “just verdict” that would reveal the names of the perpetrators and those who ordered the operation.
German prosecutors say the actions of which Serhii K. is accused – attacking civilian targets and causing explosions that destroyed infrastructure and damaged public services – would amount to a war crime. The alleged aim was to disrupt a major source of foreign revenue for Russia after its full-scale invasion of Ukraine, launched earlier that year.
He is the only person on trial but Croatian authorities have arrested another man, identified as Vladimir Z., who prosecutors believe was one of the divers in the team.
The explosion of Nord Stream sealed the end of Germany's long-standing dependence on Russian natural gas, although Moscow had already cut supplies over Berlin's support for European sanctions following Russia's invasion of Ukraine in February 2022.
Germany previously received half its natural gas imports through the Nord Stream 1 pipeline, by far the biggest and most modern Russian conduit serving western Europe, which allowed Russia to bypass Soviet-era pipelines crossing Ukraine.
The supply had been due to double with the opening of a twin pipeline, Nord Stream 2, which was already built, although Berlin cancelled approval to start operations shortly before Russia's invasion.
Methane gas
The trial, expected to continue into February, could also have domestic political implications. Germany's far-right Alternative for Germany (AfD), leading in 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.
In the initial months after the pipelines were attacked, western officials mainly pointed fingers at Russia. Moscow has always denied any involvement and called the suggestion it would blow up its own pipelines absurd. It also rejects charges that it has more recently targeted western infrastructure with so-called “hybrid” sabotage and drone attacks.
The Nord Stream system, lying at a depth of 80 to 110 metres under the Baltic and built by Russian energy corporation Gazprom to supply up to 110 billion cubic metres of gas to Germany, was formerly at the core of economic ties between the two countries.
On September 26, 2022, several blasts were detected by Swedish seismologists over 17 hours. The explosions sent huge plumes of methane gas into the atmosphere, as three of the four concrete-coated steel pipelines were ruptured.
Prosecutors allege Serhii K. travelled to Germany through Poland about three weeks before the attack, using a forged Ukrainian passport.
They say he and his group used a sailboat hired in the northern German city of Rostock to reach an area close to the Danish island of Bornholm, where they rigged specialised military-grade explosives fitted with timers to the sea floor.
The weekly Der Spiegel magazine and ZDF public television have previously reported that five men and one woman were on the rented yacht Andromeda, which left Rostock on September 6 and returned on September 23, 2022.
