UK ‘threatens to seize’ Russia-linked shadow fleet tanker in escalation of tensions

Shadow fleets are used to transport sanctioned oil around the world

The United Kingdom has threatened to seize a Russia-linked oil tanker in an escalation of tensions between the two countries over shadow fleets.

Military options to capture a rogue ship had been identified in discussions involving Nato allies, British defence sources told The Guardian.

The news comes weeks after the UK supported a US operation to seize a Russian-flagged tanker in the North Atlantic.

British armed forces supported the capture of the Marinera, a vessel initially linked to Venezuela and previously known as Bella-1, as it travelled north and eastwards through the waters between Iceland and Scotland.

Days later, a defence source confirmed to The Times that options to seize further vessels were being considered, but no timeframe was given for potential missions at the time. The Special Boats Service (SBS) would likely lead the raids, it was suggested at the time.

A French navy boat surrounds the GRINCH oil tanker, intercepted by France in the Alboran Sea on suspicion of operating under a false flag and belonging to Russia's shadow fleet that enables Russia to export oil despite sanctions, and diverted to the port of Marseille-Fos, in the Gulf of Fos-sur-Mer, near Martigues, France, January 25, 2026. (REUTERS)

Officials had reportedly identified legal grounds under the Sanctions and Anti-Money Laundering Act (2018), which would allow British soldiers to raid and detain oil tankers.

The Ministry of Defence (MoD) said at the time: “It has been the longstanding policy of successive governments not to comment on the activities of special forces.”

Around a fortnight ago, the French navy working with intelligence provided by the United Kingdom intercepted an oil tanker in the Mediterranean Sea that traveled from Russia, officials said.

Maritime law states that ships must be registered to a specific country or territory and display its flag, but if a ship fails to do this it could be deemed stateless. This would have to be established for the UK to seize a vessel.

Seized ranker Marinera rakes Shelter in the Moray Firth (Getty Images)

The use of shadow fleet tankers to move sanctioned oil around the world has increased in recent years as states seek to circumvent restrictions to their transportation.

Shadow fleets often operate under deceptive practices including the use of fake flags.

It is difficult to determine the locations of the vessels, but data collated by FleetLeaks shows the real-time position and compliance status of hundreds of vessels operating under international sanctions.

Several ships appear to be operating in the North Sea in the regions between the UK, Denmark, Sweden, Norway and the Netherlands, flying the flags of Oman and Sierra Leone.

Others are sailing in the Baltic Sea in waters bordering Sweden, Poland, Lithuania, Latvia, Estonia and Denmark, or through the Norwegian Sea.

Defence Secretary John Healey previously publicly justified the action to seize the Marinera, saying: “This ship, with a nefarious history, is part of a Russian-Iranian axis of sanctions evasion which is fuelling terrorism, conflict and misery from the Middle East to Ukraine.”