Swedish prosecutors announced today that they are dropping further investigations into the gas pipeline explosions Nord Stream 1 and 2confirming earlier media reports.

“The conclusion of the investigation is that Sweden has no jurisdiction and that the investigation should therefore be closed,” the Swedish public prosecutor’s office said in a statement.

The multibillion-dollar Nord Stream pipelines, which carried Russian gas to Germany through the bottom of the Baltic Sea, were punctured by a series of explosions in Swedish and Danish waters in September 2022, releasing large amounts of methane into the atmosphere.

Danish police have said the pipelines were hit by powerful explosions, and Swedish investigators have confirmed traces of explosives were found, proving sabotage.

Sweden, Denmark and Germany launched separate investigations into the pipeline explosions, tightly controlling the information released from those investigations. The Danish and German investigations are ongoing.

Reuters notes that unless hard evidence is found in any of the ongoing investigations, the mystery behind one of the most brazen acts of infrastructure sabotage in modern history may remain unsolved.