Finland's national power grid operator said on Thursday it had asked a Helsinki court to seize the Eagle S oil tanker in a bid to secure the company's claim for damages related to the breakdown of the undersea Estlink 2 electricity interconnector.

Finnish police said on Thursday they are investigating whether a foreign ship was involved in the damage of an undersea power cable connecting Finland and Estonia following a sudden outage on Wednesday.

The damaged cable is one of several recent incidents in the Baltic Sea under investigation as possible acts of sabotage.

Finnish police said on Sunday they had found tracks that drag on for dozens of kilometres along the bottom of the Baltic Sea where a tanker carrying Russian oil is suspected of breaking a power line and four telecoms cables with its anchor.

On Thursday, the Finnish transmission line operator Fingrid filed a request in a Helsinki court to seize the tanker Eagle S to secure potential compensation claims. It is suspected that the vessel damaged the EstLink 2 subsea power link.

Finnish law enforcement suspects another crew member of a Russian shadow fleet tanker in the severing of underwater cables, bringing the total number of suspects to eight, Yle reports. The list of suspects has grown to include another crew member,