A Finnish court on Friday denied a request for the release of an oil tanker suspected by police of damaging an undersea power line and four telecommunications cables in the Baltic Sea last week.

Finland on Dec. 26 seized the Eagle S tanker carrying Russian oil on suspicion that it damaged the Finnish-Estonian Estlink 2 power line and the telecoms cables the previous day by dragging its anchor across the seabed.

A lawyer representing United Arab Emirates-based Caravella LLC FZ, which owns the tanker, had sought the release of the vessel and crew.

"This district court has rejected the claim of the defendant, which means that this seizure remains in force," Helsinki District Court Judge Tatu Koistinen said.

Finnish lawyer Herman Ljungberg, who represented Caravella, said the company now planned to file a new motion for the vessel's release.

Baltic Sea nations are on high alert after a string of outages of power cables, telecom links and gas pipelines since Russia invaded Ukraine in 2022. NATO said last week it would boost its presence in the region.

The Finnish customs service believes the Eagle S is part of a shadow fleet of aging tankers being used to evade sanctions on the sale of Russian oil.

The vessel, which is registered in the Cook Islands, was brought to a bay near Finland's port of Porvoo where police are currently collecting evidence and questioning the crew who are Georgian and Indian citizens.

Finnish police have said eight crew members are suspects in the investigation.