Four years after the explosions that tore through the Nord Stream gas pipelines, a Ukrainian man is standing trial in Hamburg over the attack. German prosecutors accuse Serhii K of conspiring with other Ukrainian military personnel to destroy the pipelines and cut off the gas revenue Russia was using to fund its war.
Serhii K was extradited to Germany from Italy late last year and denies the charges. A second suspect, who is fighting extradition from Croatia, also denies involvement.
The case is highly sensitive in Germany, which has been one of Ukraine's closest allies since Russia launched its full-scale invasion in February 2022, about seven months before the attacks. On 26 September 2022, explosives destroyed three of the four gas pipelines off the Danish island of Bornholm.
Immediately after the blasts, Western suspicion pointed towards Moscow, though without direct accusation. Russia had already shut off gas supplies through Nord Stream 1 weeks before the attack, and Nord Stream 2 had never been switched on. Berlin had frozen that project shortly before the invasion, and there were reports of suspicious Russian naval movements in the area before the explosions.