European Union naval forces boarded the tanker MV South Star in the Mediterranean Sea on July 20, the first time the bloc has physically inspected a vessel from Russia's so-called shadow fleet, EU foreign policy chief Kaja Kallas said on July 22. The ship is suspected of sailing under a false flag, a violation of international maritime law, Kallas said.
The inspection was carried out as part of Operation IRINI, the EU's Mediterranean mission. The formal reason was to verify the vessel's flag and registration. The tanker was sailing under the flag of Cameroon — and, according to Ukrainian intelligence, also uses the flag of Guinea-Bissau. The IRINI mission specified that the South Star is under EU sanctions, and the inspection was conducted under Article 110 of the UN Convention on the Law of the Sea, which allows foreign vessels to be checked if they are suspected of lacking registration.
“Every illegal voyage helps sustain Russia's war machine. We are backing our sanctions with action at sea,” Kallas wrote on the social media platform X. She said that this week EU member states expanded the mandate of Operation ATALANTA, allowing it to conduct similar inspections of vessels off the coast of Somalia. This increases restrictions against Russia's shadow fleet, the diplomat noted.
According to the maritime intelligence service Starboard Maritime Intelligence, the South Star left the port of Tunis in early July, crossed the Mediterranean and spent several days off the coast of Egypt. There it met with the Russian tanker PASSAT and the Egyptian vessel Golden Ocean 1. After that, on June 17, the vessel headed back and disappeared from radar on July 20, then turned its AIS back on on July 21 off the Tunisian coast. As of publication, the tanker remains in the Gulf of Tunis.
The South Star has called at Russian ports on the Black Sea many times. Ukrainian intelligence claims the vessel is used as a floating transshipment hub for Russian oil products delivered from the ports of Tuapse, Novorossiysk and others to the area of Greece and Cyprus. In addition to EU sanctions, the tanker is under Ukrainian, Canadian, Australian, Swiss and New Zealand sanctions.
Since the start of the year, EU and UK authorities have detained five tankers linked to Russia's shadow fleet. In January, French naval forces stopped the Grinch; in March, the Deyna; and on May 31, the Tagor. All three were later released. The fourth was the Smyrtos, detained by British Royal Marines on June 14 in the English Channel. After that, the use of the English Channel route by sanctioned vessels dropped by about 40%; 75% of them now choose a route north of Scotland, between the Faroe and Shetland Islands.
Operation IRINI has been active in the central Mediterranean since 2020. It was originally created to monitor compliance with the UN arms embargo on Libya. In 2025, the EU Council expanded its mandate to include gathering information on threats to critical maritime infrastructure. In March 2026, the operation's forces were authorized to board vessels to check flags. Russia's Foreign Ministry has called the tanker detentions “piracy” and denied the existence of a “shadow fleet” under international maritime law.