Finnish authorities suspect that the Eagle S oil tanker and its anchor have damaged the Estlink 2 power cable.
The crew of the Eagle S vessel consists of over 20 individuals who are citizens of Georgia and India, according to Sami Paila, Head of Investigation at the National Bureau of Investigation (NBI). Paila did not comment on the nationality of the officers.
According to Paila, some of the crew members are suspects, while others are witnesses. The status of some members is still unclear. Paila did not comment on the current number of suspects.
No arrests or detentions have been made on the vessel as of now.
The tanker is suspected to be part of Russia's so-called "dark", or "shadow" fleet. Yle compiled the ship's movements in and around Finnish waters.
1. Tanker near Porkkala
The Finnish Border Guard patrol vessel Turva escorted the tanker off Porkkala in the early evening on Wednesday, Christmas Day.
The Border Guard patrol ship Turva contacted the Eagle S for the first time on Christmas Day at around 6:30 pm, Helsinki Police Chief Inspector Juha Hietala told Finnish News Agency STT.
According to Hietala, permission for a helicopter operation was already given when the ship was contacted.
The oil tanker was in the possession of the authorities in Finnish territorial waters at around half past midnight on Thursday, Boxing Day.
In the graphic below you can see how Turva was also patrolling very close to the tanker on Thursday afternoon. According to the website Vesselfinder, the distance between the vessels was about 500 metres.
2. Roundabout turns on Christmas Day
The Eagle S, which left the port of Ust-Luga in Russia, was on its way to Port Said, Egypt.
However, on Wednesday afternoon, Christmas Day, it made a U-turn, according to the website Marine Traffic. The tanker turned back towards Russia at around 1:50 pm Finnish time and proceeded about half a kilometre backwards on its route.
It then hooked back onto its original route at around 2:20 pm. The manoeuvre occurred about an hour and a half after the ship had crossed the Estlink 2 cable.
The reason behind this series of turns is not yet known.
The graphic below shows the movements:
3. Tanker near cable at time of incident
The Estlink 2 cable connection was disrupted on Christmas Day at 12:26 pm, according to grid operator Fingrid.
Maps on the Marinetraffic website show how the vessel was moving over the cable at the time of the incident:
Police suspect tanker damaged telecom cables
The Eagle S tanker sailed over several underwater communication cables around the same time the operating companies detected damage.
The tanker passed over the data cables between 6 and 7 pm on Wednesday evening, according to the MarineTraffic service, which tracks maritime traffic.
Two of the damaged cables are owned by telecom operator Elisa. In addition to Elisa’s cables, authorities also reported disruptions in two other data cables belonging to Chinese-owned CITIC Telecom and Finnish state-owned company Cinia.
According to Elisa's security director Jaakko Wallenius, the company detected the breaks because its system immediately alerted them to the issue.
The damage occurred just a few hours after the Estlink 2 electricity cable between Finland and Estonia suffered damage.
The Finnish police suspect the Eagle S vessel of being responsible for the cable damage.
The tanker is currently in the custody of the Finnish authorities off Porkkalanniemi, about 15 kilometres offshore.
Police is conducting a preliminary investigation on board.
The map below shows where the tanker is now.
