Investigators have found traces of explosives at the site of the damaged Nord Stream pipelines, confirming that the underwater explosion was caused by an act of sabotage, a Swedish prosecutor said on Friday.

Swedish and Danish authorities are investigating four holes in the Nord Stream 1 and 2 gas pipelines which link Russia and Germany via the Baltic Sea and have become a flashpoint in the Ukraine crisis.

Last month Denmark said that a preliminary investigation had shown that the leaks were caused by powerful explosions.

“Analysis that has now been carried out shows traces of explosives on several of the objects that were recovered,” the Swedish Prosecution Authority said in a statement.

The #Swedish Security Service confirms sabotage of #NordStream pipelines.

The investigation documented extensive damage to the pipelines and seized several "foreign objects" on which explosive residues were found. pic.twitter.com/Zev0DtNnQS

— NEXTA (@nexta_tv) November 18, 2022

“The investigation is highly complex and comprehensive. The ongoing probe will determine whether any suspects can be identified,” it added. No further comments were given.

Early findings

Seismologists in Denmark and Sweden have previously said they had registered tremors in the immediate vicinity of the leaks and that the signals did not resemble those from earthquakes.

The September 26 ruptures spewed large amounts of gas into the ocean in the week that followed, triggering warnings of public hazard and fears of environmental damage.

A section measuring at least 50 metres (164 feet) is missing from Nord Stream 1, Swedish daily Expressen reported on October 18 after filming what it said was the first publicly released images of the damage.

Russia’s defence ministry last month said that British navy personnel blew up the pipelines, a claim that London said was false and designed to distract from Russian military failures in Ukraine.