The Eagle S – a tanker ship carrying Russian oil and suspected of severing the Estlink 2 power cable running under the Baltic Sea between Finland and Estonia – was reportedly brimming with spy equipment.

Finland has seized an oil tanker suspected of having severed undersea power and internet cables, with Finnish authorities saying the vessel may have been part of Russia's "shadow fleet" of ships aimed at skirting Western sanctions.

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.