The Finnish authorities said the tanker might be part of Russia’s shadow fleet, which emerged as a way to circumvent Western-imposed price caps on Russian oil transported by sea. The caps were introduced several months after President Vladimir V. Putin of Russia ordered the full-scale invasion of Ukraine in February 2022.

Police in Finland are investigating what they called "grave sabotage" and have taken command of Eagle S, an oil tanker believed to belong to a so-called shadow fleet of ageing tankers which seek to evade Russian 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.