UK gas prices soared on Tuesday after it emerged that Finland’s government believes a leak in an underwater pipeline was caused by “external activity”.
A statement by Finnish president Sauli Niinisto said a communications cable had also been damaged.
“The damage to the underwater infrastructure has been taken seriously and the causes investigated since on Sunday,” he said.
He said it is “likely” the damage was caused by “external activity”, and added that he has been in contact with Nato.
Prime Minister Petteri Orpo said it appears the leak could not have been caused by normal activities.
The gas pipeline, which started to leak over the weekend, runs between Finland and Estonia, across the bay of Finland.
It comes into land some 25-31 miles (40-50km) to the west of the two countries’ capitals, Helsinki and Tallinn.
UK gas prices jumped 12.7% to 123.2p per therm on Tuesday after Swedish Radio, Finnish newspaper Iltalehti and state broadcaster Yle all reported that the leak was not thought to be an accident.
The Finnish government has called a press conference at 5.30pm local time (3.30pm BST).
Researchers in Estonia are reported not to have noticed any seismological activity, which could indicate an explosion.
On Sunday morning, the Balticconnector pipeline in the Gulf of Finland, which is shared by the two countries and Russia, was taken out of service due to a suspected leak.
The operators of the pipeline said they had noticed an unusual drop in pressure at around 2am local time.
They have not yet said what they think might have caused the leak, but the companies warned that if they find a leak it could take months to repair.
It comes a little over a year after explosions hit the Nord Stream 1 and 2 pipelines in the Baltic, which transported gas from Russia to Germany.
The Balticconnector pipeline, which opened in 2020, is used to send gas between Estonia and Finland, depending on which country is most in need at any point.
Both countries said their energy security is not under threat due to the potential leak.
