Finland authorities investigate underwater cable damage in the country’s Gulf – JURIST

Finnish police announced on Wednesday that they are investigating damage to an undersea telecommunications cable in the Gulf of Finland after seizing a vessel suspected of causing the incident.

According to a police statement, telecommunications authorities detected a fault in an undersea cable linking Helsinki and Tallinn, Estonia’s capital, on the morning of December 31. The discovery prompted an immediate multi-agency response involving the Defence Forces, Customs, and the Finnish Safety and Chemical Agency.

Authorities reported that Finland’s border guards located a vessel within the country’s exclusive economic zone (EEZ) that is suspected of having caused the damage. The ship was subsequently taken under Finnish control and moved to a secure anchorage within Finnish territorial waters, with responsibility for the investigation transferred from the Gulf of Finland Coast Guard to the Helsinki Police Department. The case is being investigated under Finland’s criminal code as aggravated criminal damage, attempted aggravated criminal damage, and aggravated interference with telecommunications.

Police said on Thursday that investigative measures had been carried out aboard the detained vessel, including the collection of evidence and an examination of the anchor. Two members of the crew were arrested, and two others were placed under travel restrictions. Authorities did not disclose any details about the crew members’ nationalities or roles. Investigations will continue in cooperation with national and international authorities, with further updates to follow.

This is not the first disruption of undersea infrastructure in the Gulf of Finland. In December 2024, Finnish authorities detained a vessel suspected of damaging an undersea power cable linking Finland and Estonia. At the time, the European Union condemned the incident, with EU officials linking it to Russian “shadow fleet” vessels allegedly used to circumvent Western sanctions and describing the damage as part of a broader hybrid threats tactic targeting critical infrastructure in the Baltic Sea.

A similar incident occurred in January 2025, when Finnish authorities seized an oil tanker suspected of involvement in damage to undersea cables and a power line in the region. Diplomatic relations between Finland and Russia have deteriorated since Finland joined the North Atlantic Treaty Organization (NATO) in 2023, resulting in strained dialogue, mutual accusations, and border closures.