Finland last month seized the Eagle S tanker carrying Russian oil on suspicion that the vessel had damaged the Finnish-Estonian Estlink 2 power line and four telecoms cables by dragging its anchor across the seabed.
"The location where the anchor was found is along the route of the Eagle S ... towards the western end of the drag trace found on the seabed," Finland's National Bureau of Investigation said in a statement.
Finnish lawyer Herman Ljungberg, who represents the ship's owner, United Arab Emirates-based Caravella LLC FZ, said the alleged damage happened outside of Finland's territorial waters and that the country thus lacked jurisdiction to intervene.
Ljungberg has previously said Finland hijacked the vessel at sea and should release it, a request that was denied by a court last week.
Members of the Eagle S crew are suspected of sabotage and damage to property, and may also face criminal liability along with the ship's owner for the disruption of telecommunications, Finland's Deputy Prosecutor General Jukka Rappe told Reuters.
Finnish police have said they ordered a travel ban for eight crew members as part of the investigation.
Finland's customs service has said it believes the Eagle S is part of a shadow fleet of tankers used to circumvent sanctions on Russian oil, and has impounded its cargo.
The Kremlin has said Finland's seizure of the ship is not a matter for Russia.
Repairing the Estlink 2 power cable that was broken along with the telecoms cables is expected to take seven months, operators Fingrid of Finland and Elering of Estonia have said.
