The trial of the year begins at the Higher Regional Court in Hamburg. Serhii K. is accused of having blown up the pipelines as an officer of a Ukrainian commando. He has remained silent so far.
Serhii K. is suspected of having planted explosive devices on the Nord Stream pipelines with a group in September 2022.
He was arrested in Italy in August 2025 and has so far remained silent about the allegations, while investigators are presenting extensive evidence with experts, witnesses and telephone surveillance.
His defense lawyers have announced that they will question the evidence of K.'s presence on the yacht; They also criticize the prison conditions and the arrest warrant.
The Higher Regional Court rejected the Nord Stream stock corporations as co-plaintiffs because no existential damage was said to have occurred for them.
Berlin. Four years after large quantities of abruptly escaping methane gas tore open hundreds of meters of the Nord Stream pipelines and turned the Baltic Sea near Bornholm into a foaming whirlpool, what is probably the most spectacular sabotage attack in German post-war history is being investigated by the judiciary.
On September 26, 2022, timed explosive devices exploded, destroying three of the four gas pipelines known as Nord Stream 1 and 2. As of Wednesday, 50-year-old Serhii K. will have to answer before the State Security Senate of the Hanseatic Higher Regional Court in Hamburg.
According to the Federal Prosecutor General's indictment, a group under the command of the former Ukrainian officer is said to have planted the explosive devices. Against the background of the Russian war of aggression against Ukraine and German support for Ukraine, the process is considered politically highly explosive.
What exactly is Serhii K. accused of?
In September 2022, Serhii K. is said to have commanded a small group of civilian divers and military personnel on board the yacht “Andromeda”. The Federal Public Prosecutor's Office accuses six men and one woman of planting the explosive devices at a depth of 80 meters.
The officer is charged with a war crime under Section 11 of the International Criminal Code. The prosecution argues that the lines were civilian objects protected by international humanitarian law and did not represent a legitimate military target.
The indictment also lists further allegations under the Criminal Code, including causing an explosive explosion in six cases, destroying buildings and disrupting public operations. The State Security Senate approved the indictment because Serhii K. “appears sufficiently suspicious to the chamber as an accomplice.”
What is known about Serhii K.?
The accused is 50 years old and was serving in the Ukrainian army in a special operations unit at the time of the crime. His rank was comparable to that of a German captain.
According to the Federal Prosecutor General's Office, he is suspected of having developed a plan with other military officers after the Russian attack on Ukraine to attack the Baltic Sea gas pipelines in order to permanently deprive Russia of income from gas sales.
Equipped with false identification documents, his group is said to have set sail on the charter yacht from the port in Wiek on Rügen and crossed the Baltic Sea for several days. Several witnesses noticed them in ports in Sweden and Poland. The professional divers are said to have placed explosive charges on the pipelines, which were previously disguised as diving bottles.
The investigations by the Federal Police and BKA are considered very thorough, even in defense circles. The list of witnesses and evidence for the trial alone is apparently almost 30 pages long. There are numerous expert reports, eyewitness reports and speed camera photos of cars in which the alleged perpetrators are said to have driven to the coast.
Why is the process politically explosive?
In addition to the Russian energy company Gazprom (51 percent), the German Winterschall Dea AG (15.5 percent), Eon as well as a French and a Dutch company were involved in the consortium behind Nord Stream 1. Nord Stream 2, on the other hand, was a wholly owned Gazprom subsidiary.
Through the more than 1,200 kilometers of pipelines, around half of Germany's annual gas consumption was imported in 2021. At the time of the blasts, gas was no longer flowing because Russia had blocked Nord Stream 1 due to alleged technical problems and Germany had not approved Nord Stream 2.
What is tricky is that the attack by a suspected Ukrainian commando would have caused damage to and in Germany, even though the country is not a party to the war and supports Ukraine in its defensive battle with arms deliveries. After the attack, gas prices in Germany rose sharply.
Ukraine and its President Volodymyr Zelensky have not yet publicly acknowledged the attacks on the Nord Stream lines.
What does Serhii K. say about the allegations?
The accused has so far remained silent about the allegations. This behavior is to be expected. The officer will most likely face serious prosecution in Ukraine if he reveals details about a command operation abroad.
After he was arrested in August 2025 while vacationing in Italy in the province of Rimini, authorities monitored his phone calls. According to the prosecution, he was overheard saying that he felt abandoned and that the time had come for his home country to commit to the military action.
What is the evidence?
Unlike a pioneer soldier, the German investigators cannot provide any final DNA evidence for Serhii K. that he was actually on the yacht. However, in the 108-page indictment they cite numerous indications that he is said to have been in charge.
According to the prosecutors' account, his cover identity was deciphered. The phone calls from prison and documents on his cell phones and storage media that dealt in detail with the pipelines are said to incriminate him. In addition, his wristwatch had permanently recorded health data in the past - with the exception of the time when the "Andromeda" was traveling in the Baltic Sea.
What do the defense lawyers say about the allegations?
The accused is defended by the German criminal lawyers Lars Brögeler and Jes Meyer-Lohkamp as well as the human rights lawyer Nicola Canestrini from Italy. Canestrini had already represented Serhii K. in the extradition proceedings with the Italian justice system and speaks fluent German.
When Handelsblatt spoke to the lawyer on the phone on Friday, he did not want to anticipate a possible opening statement. According to reports, various lines of defense are conceivable. Above all, the lawyers are likely to question whether the Ukrainian's presence on the yacht can actually be proven. They could also assume that he was only following orders from his superiors or that the pipelines could perhaps be seen as a legitimate target.
Since Serhii K.'s extradition, Canestrini has made serious allegations against the German judiciary. The European arrest warrant did not contain the accusation of war crimes and was only issued for sabotage. Important facts were therefore concealed from the Italian judiciary before his client was transferred. Canestrini criticizes the prison conditions as “inhumane”. Serhii K. is in a cell 23 hours a day with no contact with fellow prisoners.
Why is there no co-plaintiff?
At the end of September, the Higher Regional Court decided not to admit the two Nord Stream stock corporations as co-plaintiffs. Security circles and defense attorneys had previously feared that Russia could try to gain access to the sensitive investigation files in this way. The court justified its rejection differently: the companies did not suffer any “existential damage” as would be necessary for approval.
Although repair costs are expected to be in the mid three-digit million range, the judges wrote that this only corresponds to a fraction of the original investment totaling around 17 billion euros. At the same time, the Senate pointed out that it was not its task to “investigate any reparation demands the Russian Federation may have against Ukraine.”
What about the other alleged perpetrators?
In August, Croatian authorities arrested one of the suspected divers in Pula. Apparently he had traveled to the set of a political thriller as a consultant. US director Doug Liman (“The Bourne Identity”) is filming the story of the Nord Stream attack in Croatia with well-known actors such as Sean Penn and Adrien Brody.
It is unclear whether and when the man will be extradited to Germany. A court decided that he could be extradited, and his lawyer announced that he would take action against it in the next instance. The German authorities have apparently identified seven people who were said to have been part of the command or on board the “Andromeda”. If you travel to the EU, you must expect to be arrested and extradited to the German judiciary.
