Blasts which destroyed sections of the Nord Stream pipelines were the result of “grievous sabotage,” Swedish officials confirmed on Friday.
Prosecutor Mats Ljungqvist, who is leading the preliminary investigation, said traces of explosives were found at the site.
“The analysis showed residue of explosives on several of the foreign objects that were found,” he said.
The site in question “has been thoroughly documented,” he added.
The investigation will continue analysing the sections where the damage occurred to see “if anyone can be made suspect and later charged,” a statement said.
The pipelines, which cross the Baltic Sea to Germany from Russia, have been the focus of an investigation by authorities in Sweden after two leaks were discovered in the Nordic nation’s exclusive economic area at the end of September.
Seismology institutes reported that they had recorded two underwater explosions before the leaks appeared.
An inquiry discovered 250 metres of pipeline had been destroyed.
Swedish authorities announced in early October that they had conducted an underwater inspection of the site and that the results backed up suspicions of sabotage.
The Nord Stream group, which operates the twin Nord Stream 1 pipelines, has launched its own investigation and said it would "continue to analyse" data gathered from the site.
Russia recently accused the UK of blowing up the pipelines - a claim dismissed by Britain as "false and designed to distract from Russian military failures in Ukraine".
The pipelines, which connect Russia to Germany, have been at the centre of tension as the Kremlin cut gas supplies to Europe in suspected retaliation against western sanctions imposed over Moscow's invasion of Ukraine.
Although they were not in operation when the leaks occurred, they still contained gas, which was released into the atmosphere.
