Tonga and the Cook Islands have denounced the illegal use of their national flags after reports that at least 29 vessels were falsely identifying themselves to evade international sanctions. Maritime analysts say most of the ships are crude oil tankers moving between Iran and China, loading crude in the Persian Gulf, conducting ship‑to‑ship transfers and other maneuvers to hide the cargo’s origin, then unloading in China.
Under normal practice, ships broadcast unique identifiers via the Automatic Identification System (AIS) so authorities can track vessels and reduce collision risk. Mark Douglas, a maritime domain analyst at Starboard Maritime Intelligence in New Zealand, said 21 of the 29 tankers reported to be using Tongan or Cook Islands identities are subject to sanctions and two are transmitting invalid AIS numbers, making it harder to check their status. Crews can also switch off AIS entirely, effectively making ships invisible at sea—a tactic previously used by North Korea to dodge UN measures.
Analysts say operators also tamper with a vessel’s Maritime Mobile Service Identity (MMSI) by altering the first three digits that indicate national registration, which changes the ship’s reported nationality. Douglas noted such frauds should be exposed during port inspections, but many of these tankers avoid ports or call at ports where documentation is unlikely to be rigorously checked.
Human rights and sanctions enforcement groups have flagged similar behavior elsewhere. In late January, Amnesty International reported Myanmar’s military junta had obtained aviation fuel via ‘ghost ships’ that either flew another nation’s flag or turned off tracking systems.
Western governments have responded with tougher measures. US forces boarded the Liberian‑flagged Motor Vessel Sagitta in the Caribbean on January 20, and French authorities recently detained the Russian tanker Grinch, which had sailed from Murmansk in early January under a Comoros flag.
Both Pacific governments informed the International Maritime Organization and publicly declared the implicated vessels were not legitimately flagged. The Cook Islands announced plans for a Vessel Verification Portal to improve transparency and access to vessel information after inaccurate reports circulated that the tanker Bertha had been pictured flying its flag off Venezuela. Tongan officials warned any ship claiming the Tongan flag was doing so fraudulently, noting Tonga closed its international ship registry in 2002 and no longer registers foreign vessels on international voyages.
Paul Chamberlain, a visiting research fellow at the National Institute for Defense Studies in Tokyo, said action against so‑called shadow fleets is overdue. He warned the networks that expanded in 2022 to evade sanctions pose growing environmental and safety risks and urged Tonga, the Cook Islands and capable states to press diplomatic objections and enforce maritime law. Chamberlain added that regional powers, including China, should remind states of their responsibilities under the law of the sea.
Edited by: Darko Janjevic