Federal prosecutors allege that Serhii K. was part of a team that rented a yacht in Rostock, Germany, to carry out the explosive operations on the Nord Stream 1 and 2 pipelines, severely affecting the gas flow from Russia to Germany. Ukraine has categorically denied any involvement in the sabotage, which preceded a pivotal moment in Europe's energy crisis.

While the Nord Stream 2 pipeline was never activated, its counterpart, Nord Stream 1, was a crucial energy supplier with a 1,200 km route under the Baltic Sea. Tensions over the project escalated before the invasion, leading Germany to halt the approval of Nord Stream 2 and Russia's subsequent shutdown of Nord Stream 1. The explosions occurred on September 26, 2022, near Denmark's Bornholm Island, prompting widespread speculation regarding the identity of the saboteurs.

Although the investigation has been complex, earlier reports had indicated a team of Ukrainian divers might have executed the operation. A German arrest warrant for another suspect named Volodymyr Z. had been issued last August. Following the extradition process, Serhii K. is set to face an investigation judge as he is deemed "strongly suspected" of participating in the sabotage and causing an explosion undermining the constitutional order. However, there remains no concrete evidence linking the attacks to Ukraine or Russia as the mystery continues to unfold.