According to France, the tanker, which had sailed from Murmansk, was trying to ‘skirt international sanctions’.

The French navy with support from the United Kingdom has intercepted an oil tanker suspected of being part of Russia’s sanctions-busting “shadow fleet”.

French President Emmanuel Macron announced the interception in a post on X on Monday, saying the Tagor was boarded on Sunday in the Atlantic.

The post included a video showing a person rappelling from a helicopter onto a ship.

“It is unacceptable that boats skirt international sanctions, violate the law of the sea and finance the war that Russia has been waging for more than 4 years against Ukraine,” Macron wrote.

“These ships, that don’t respect the most elementary rules of maritime navigation, are also a threat to the environment and everyone’s security.”

According to French authorities, the tanker had sailed from Murmansk in northwestern Russia.

The ship was falsely flying a Cameroonian flag, the maritime prefecture said, and was heading towards Limbe, a seaside city in western Cameroon.

Guillaume Le Rasle, spokesman for the Atlantic maritime prefecture, said the tanker was under European Union and United States sanctions.

“It is a vessel that was known and tracked,” he told the news agency AFP.

“The decision to divert it was taken Sunday evening,” he added. “The objective of the diversion is to verify the validity of its flag.”

The tanker, which has frequently changed flags, was “almost empty” at the time of boarding, he added.

The last time it transmitted an automatic identification system signal, a week ago, the Tagor was sailing off the Norwegian coast and flying a Madagascan flag, according to the MarineTraffic tracker.

The Atlantic maritime prefecture said the interception had taken place more than 400 nautical miles (740km) west of Brittany.

Russia’s ‘shadow fleet’

Oil revenue is a key part of Russia’s economy and helps offset the cost of the more than four-year war on Ukraine.

Russia is believed to be using a fleet of hundreds of ships to evade international sanctions imposed over the war.

France and other countries have pledged to crack down on the sanction-busting “shadow fleet.”

Since September, France has boarded three other ships, but the ships were allowed to sail after their owners paid fines.

In September, the French navy boarded the Boracay, which claimed to be flagged in Benin. Its Chinese captain was put on trial in absentia, and a French court in March issued an arrest warrant and a one-year jail sentence against him.

In January, French forces impounded another suspected Russian tanker, the Grinch, and in March, the Deyna, which sailed from Murmansk under a Mozambican flag, was detained in Marseille.

In April, France announced a plan to double penalties for ships that fail to fly a flag or refuse to comply.

Several Western countries have imposed sanctions on Russian vessels over its 2022 full-scale invasion of Ukraine.

Russian President Vladimir Putin has condemned the detention of Russia-linked vessels as “piracy”.