UK forces have joined a military operation with the French navy in the Mediterranean to seize an oil tanker, with French president Emmanuel Macron identifying the vessel as part of a ‘shadow fleet’ linked to Russia. 

The Royal Navy tracked and gathered vital intelligence as part of a French operation to intercept and board a crude oil tanker in the Mediterranean.

British patrol boat vessel HMS Cutlass was dispatched to track the vessel, reporting on the ship’s movements and capturing imagery to support French forces.

“These vessels, which evade international sanctions and violate the law of the sea, are profiteers of war,” Macron wrote in a post on X. “They line their pockets while helping finance Russia’s war effort. We will not allow it.”

Macron has pledged that France would maintain pressure on Russia to end its invasion of Ukraine.

“The war involving Iran will not deflect France from its support for Ukraine, where Russia’s war of aggression continues unabated,” he wrote in English.

With global attention focused on the US-Israeli war with Iran, France will keep supporting Ukraine, Macron added.

“This morning in the Mediterranean, the French Navy intercepted and boarded another vessel from the shadow fleet. We remain resolute,” he noted on March 20.

At the prosecutor’s request, the vessel was escorted to an anchorage point for further inspection, the Maritime Prefecture of the Mediterranean said in a statement. The documents found onboard “confirmed doubts about the validity of the flag,” they said.

UK’s defence secretary John Healey MP said: “I am proud of the support our UK Armed Forces provided to this French operation. Disrupting, deterring and degrading Russia’s shadow fleet and starving Putin’s war machine of funds is a priority for this government and we will continue to take action alongside our allies.”

This operation comes in the same week a Royal Navy warship and helicopter completed a focused 48-hour operation monitoring Russian activity in UK waters as part of coordinated NATO efforts.

Portsmouth-based HMS Mersey and a Wildcat helicopter from 815 Naval Air Squadron were dispatched to report on the movements of a Russian frigate and a sanctioned oil tanker in the English Channel.