EU Stops Sixth Tanker in Mediterranean Over Russian Oil Shadow Fleet and UNCLOS Flag Verification
The European Union (EU) has stopped a sixth tanker in the Mediterranean suspected of operating under a false flag as part of the Russian oil shadow fleet, intensifying enforcement of EU sanctions and maritime regulations. On Sunday, August 30, forces from the Italian patrol boat ITS Paolo Thaon di Revel were seen boarding the tanker using helicopters and launches to conduct an inspection.
Kaja Kallas, Vice-President of the European Commission and EU High Representative for Foreign Affairs and Security Policy, confirmed the boarding and described it as a “flag verification.” She said it was the sixth tanker that EUNAVFOR IRINI has stopped for verification since its mandate was expanded earlier this year. The operation is being carried out under Article 110 of the United Nations Convention on the Law of the Sea (UNCLOS), giving the mission an important legal framework for conducting flag-verification activities.
Tanker Sun Linked to Suspected False-Flag Operations
The tanker, operating under the name Sun, reported registration in Cameroon, which was established in 2026. According to information in the Equasis database, the vessel had previously been listed in 2025 as sailing under false flags from Timor-Leste and Benin.
The crude oil tanker has a deadweight capacity of 159,186 tonnes and was built in 2005. It is listed as being owned and managed from Turkey and is in the Russian class.
According to its Automatic Identification System (AIS), the tanker was sailing from Novorossiysk, Russia. However, photographs showed the vessel sailing in ballast. Its AIS indicated that it was heading toward Denmark and was waiting for orders.
The tanker is already subject to EU and UK sanctions. It was also inspected in July at Novorossiysk, where deficiencies involving firefighting equipment, buoys and alarms were recorded. The vessel was not detained at that time.
UNCLOS Provides Legal Basis for Flag Verification
Operation IRINI was originally established in 2020 under a United Nations mandate to enforce an arms embargo on Libya in the Mediterranean. Since March, however, the operation has had an expanded “right of visit for flag verification” under Article 110 of the United Nations Convention on the Law of the Sea (UNCLOS).
Under the expanded mandate, IRINI forces can board a vessel, inspect its documents and collect “relevant information” for assessment and reporting to EU authorities.
The development highlights the growing importance of maritime law, vessel registration and flag-state verification as European authorities increase scrutiny of ships suspected of supporting Russia’s oil trade through the shadow fleet.
EU Targets Russian Oil Shadow Fleet
The European Union has sanctioned more than 600 tankers as part of its efforts to restrict Russian oil exports.
Kallas said illegal oil sales involving shadow fleet vessels represent a critical lifeline for Russia’s war in Ukraine and added that the EU would continue efforts to cut them off. She also said action against the shadow fleet would be among the issues discussed when EU defense ministers meet in Ireland on Tuesday.
Why the Tanker Inspections Matter
The latest inspection reflects a broader European effort to strengthen sanctions enforcement, maritime security and compliance with international maritime law. Flag verification is particularly significant because a vessel’s declared flag determines which state normally exercises jurisdiction over it at sea.
The use of Article 110 of UNCLOS by EUNAVFOR IRINI also places the inspections within an established framework of international maritime law. At the same time, the operation illustrates the practical challenge authorities face when dealing with vessels suspected of changing or falsely claiming registration.
Unlike some actions taken by France, Sweden, Belgium, the UK and other countries, the IRINI operations described in this case have involved inspections rather than the seizure of vessels or their direction into port.
Second Italian Tanker Inspection This Month
This is the second report this month involving an Italian frigate stopping a tanker for inspection. At the beginning of August, the Italian vessel inspected the product tanker Toa Payoh, which has a deadweight capacity of 51,000 tonnes, southwest of Sicily.
The tanker was also claiming registration in Cameroon. Vessels claiming registration in the African nation have raised concerns because of a high level of fraud, while Cameroon suspended its registries this year under pressure from European authorities and others.
In May and June, EUNAVFOR IRINI stopped four other tankers for inspections.
The latest operation therefore brings the number of tanker inspections carried out by IRINI under its expanded flag-verification mandate to six, adding another chapter to Europe’s efforts to monitor the Russian oil shadow fleet, strengthen sanctions enforcement, and verify vessel registration in the Mediterranean.
