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.

Police and media reports say that Finnish authorities have detained a Russia-linked ship as they investigate whether it damaged a Baltic Sea power cable and several data cables.

Finland is investigating the possible Christmas Day “sabotage” of an undersea power cable linking the country with Estonia under the Baltic Sea.