British forces have seized a Russian-linked oil tanker, the Smyrtos, in the English Channel on Sunday, in what Prime Minister Keir Starmer described as a significant setback for Moscow's efforts to fund its war in Ukraine.

The operation marks the first time UK forces have boarded and detained a vessel from Russia's so-called "shadow fleet," a network of tankers used to transport Russian oil and circumvent Western sanctions imposed after Moscow's full-scale invasion of Ukraine in 2022.

Following the raid, officers from the National Crime Agency (NCA) arrested an Indian national on suspicion of sanctions offences. The United Kingdom Ministry of Defence (MoD) confirmed the seizure of the tanker Smyrtos, which was carrying 700,000 barrels of Russian oil and sailing under a Cameroonian flag. It had departed the Russian Baltic port of Ust-Luga on June 5 and was bound for Port Said in Egypt.

Prime Minister Starmer stated that the successful operation delivers "yet another blow to Russia and reminds those fuelling [Russian President Vladimir] Putin’s war in Ukraine that we will not let them hide." The NCA confirmed that 24 Georgian and Indian crew members remained aboard the vessel, which is now anchored off the Dorset coast.

The MoD reported that Royal Marines commandos and NCA officers boarded the tanker in a predawn raid on Sunday, descending onto the vessel with ropes from Chinook helicopters. The operation was supported by other military aircraft, a Royal Navy frigate, and a minehunter, and lasted six hours.

The tanker Smyrtos is recorded as being owned by a Hong Kong-registered company, Zhao Yao Shipping Ltd, which reportedly owns several other sanctioned tankers. Its management company is listed as being in India's Tamil Nadu state. The tanker will be moved to England's south coast and monitored for any environmental or safety concerns.

The operation proceeded despite the presence of a Russian warship, the Admiral Grigorovich, which has been stationed near the UK since April and has escorted numerous Russian tankers through the English Channel. It remains unclear how close the Russian warship was to the Smyrtos at the time of the raid.

This seizure highlights the ongoing efforts by Western nations to enforce sanctions against Russia and disrupt its oil revenue streams, which are crucial for funding its military activities. The use of the "shadow fleet" by Russia has been a persistent challenge for international authorities seeking to monitor and control the trade of Russian oil.