Dzirhan Mahadzir – June 3, 2026 12:02 PM
The French Navy seized sanctioned tanker MT Tagor on Sunday while it operated in the Atlantic, marking the service’s fourth shadow fleet seizure since September.
The tanker was seized on suspicion of flying a false Cameroonian flag and diverted to France, arriving Tuesday in Douarnenez Bay where the ship is detained, the Maritime Prefecture of the Atlantic announced Monday. Headed by a naval officer, the Maritime Prefect is France’s representative at sea, responsible for maritime safety.
The seizure occurred 400 nautical miles west of the tip of the French peninsula of Brittany. Tagor reportedly traveled from Murmansk, Russia, according to the Maritime Prefect. The operation was conducted by French and U.K. forces on the basis of Article 110 of the United Nations Convention on the Law of the Sea for the purpose of verifying the nationality of the tanker.
The boarding team examined the tanker’s documents and confirmed the irregularity of the flag flown. A report was filed with the public prosecutor in Brest, who has jurisdiction over maritime matters.
“In accordance with international law and at the request of the public prosecutor, the vessel was diverted. It is currently being escorted by French Navy vessels to an anchorage for further investigation,” reads the release.
French President Emmanuel Macron on Monday posted a video of the operation on his X social media account. The video showed an armed boarding team descending from a French Navy NH90 Caiman helicopter onto the tanker.
“The French Navy intercepted a new tanker under international sanctions yesterday morning, originating from Russia: the Tagor. Our determination is steadfast and unwavering. This operation was carried out in the Atlantic, in international waters, with the support of several partners including the United Kingdom, in strict compliance with the law of the sea. It is unacceptable for ships to circumvent international sanctions, violate the law of the sea and fund the war that Russia has been waging against Ukraine for more than [four] years. These vessels, which fail to adhere to the most basic rules of maritime navigation, also pose a threat to the environment and to everyone’s safety,” reads Macron’s X post.
The French did not identify the French Navy ship involved in the interception though the French Armed Forces operational status update for May 21-28 said a FREMM-class frigate was operating in the North Atlantic on an independent situational awareness mission.
The BBC, citing a U.K. Ministry of Defense spokesperson, reported that a Royal Navy helicopter operating from frigate HMS Somerset (F82) provided tracking and monitoring in support of the French operation. Somerset is operating with an embarked Merlin Mk 2 anti-submarine warfare (ASW) helicopter, the frigate is currently deployed on the Royal Navy’s Operation CETO, a standing mission focused on monitoring submarine activity and screening the U.K.’s ballistic missile submarines when they deploy.
The U.K. previously supported French seizures of sanctioned tanker MT Grinch in January and MT Deyna in March in the Mediterranean, with fast patrol boats from the Royal Navy’s Gibraltar Squadron tracking the tankers. U.K. Prime Minister Keir Starmer announced in March that the U.K. military now has the authority to board ships sanctioned by the U.K. around its waters. To date, the U.K. had not conducted any boardings of sanctioned ships.
Russia condemned the French Navy’s operation with Kremlin spokesperson Dmitry Peskov describing the boarding and seizure as illegal and an act of piracy. The Russian Foreign Ministry denounced the operation in a statement issued by spokesperson Maria Zakharova. Zakharova said that while international law permitted the stopping and in limited circumstances, inspection on the high seas, it did not allow the forcible diversion of a ship to a port of the warship’s home country.
“The Russian Embassy in France has demanded that Paris provide full details of the circumstances surrounding the detention and is taking comprehensive steps to protect the Russian nationals among the crew,” Zakharova said.
Tagor’s captain, according to media reports, is a Russian national.
The head of the French Armed Forces, General Fabien Mandon, posted pictures of the operation on his official X account.
“Yesterday, a Marine Nationale vessel conducted, in international waters, a flag state inspection that confirmed the irregularity of the flag flown by the tanker-cargo Tagor. This 4th intervention since September 2025 illustrates our permanent vigilance toward those who seek to circumvent international law,” Mandon said.
France, in September 2025, detained tanker MT Boracay as it sailed near France. This was followed by the detention of Grinch and Deyna this year. All three ships were released following the payment of fines, though Boracay’s captain was subsequently tried without appearing in court on charges of failing to obey orders during the interdiction. He departed with the tanker when it was released and allowed to resume its journey to the Suez canal in October 2025. He was sentenced in March to one year in jail. The French military also supported Belgium in its seizure of Russian shadow fleet tanker MT Ethera in February.
Dzirhan Mahadzir
Dzirhan Mahadzir is a freelance defense journalist and analyst based in Kuala Lumpur Malaysia. Among the publications he has written for and currently writes for since 1998 includes Defence Review Asia, Jane’s Defence Weekly, Navy International, International Defence Review, Asian Defence Journal, Defence Helicopter, Asian Military Review and the Asia-Pacific Defence Reporter.