UK forces helped US seizure of tanker, says MoD

British armed forces supported the US seizure of a Russian-flagged oil tanker in the North Atlantic on Wednesday, the Ministry of Defence has said.

The Marinera, a Venezuelan-linked tanker previously known as the Bella 1, was stopped by the US Coast Guard, as it travelled northwards through waters between Iceland and Scotland.

The MoD said the US asked the UK for assistance, and RAF surveillance aircraft and a Royal Navy support ship, the RFA Tideforce, took part in the operation.

Defence Secretary John Healey said the action was “in full compliance with international law”, adding the UK “will not stand by as malign activity increases on the high seas”.

In a statement to MPs on Tuesday explaining why the UK joined the operation, Healey said the government was “stepping up activity against shadow vessels”.

The Marinera is accused of being part of shadow fleet carrying oil for Venezuela, Russia and Iran, breaking US sanctions.

The US Coast Guard had a warrant to seize the ship, and had tried to board the tanker last month in the Caribbean. But the tanker dramatically changed course, changed its name, and re-registered as a Russian vessel, and for two weeks the US has been pursuing it.

Healey said: “By assisting our US allies in taking this ship off the seas, we are protecting the British people and our nation.”

He said the ship had a long history of “nefarious activity” linked to Russia and Iran, and that Iran was a “persistent danger” to the UK.

The vessel, which has been sanctioned by the US since 2024, had moved 7.3 million barrels of oil on behalf of Iran, Healey said, “the proceeds of which have been used to finance terrorism, threat and instability across the world”.

He also said the shadow fleet was “vital to Putin’s ongoing illegal invasion and war in Ukraine”.

Shadow fleets, or ghost fleets, are becoming increasingly common, with Venezuela, Iran and Russia all accused of using them to avoid sanctions on oil.

Financial intelligence firm S&P Global estimates that one in five oil tankers worldwide are used to smuggle oil from sanctioned countries. The ships are often ageing tankers and use false flags to try and avoid detection.

Healey praised the “courage” of the US forces in the operation, and said no UK personnel took part in the boarding of the ship.

The seizure of the Marinera came as the US said it had seized the Sophia, another tanker with connections to Venezuela, in the Caribbean – and days after a military operation in Caracas to remove President Nicolás Maduro from power.

In a statement, the MoD said the Marinera was also assessed to have been involved in illegal activity linked to Lebanon-based militant group Hezbollah.

It said: “The ship, initially flying a false flag, turned off its transponders while at sea and sought to reflag while being pursued.”

Moscow says the Marinera was only temporarily flagged as a Russia vessel, and that “no state has the right to use force against vessels properly registered in other countries’ jurisdictions”.

It also demanded the US ensure “humane and proper treatment” of Russian citizens on board.