A series of emails from New Zealand’s Ministry of Foreign Affairs and Trade (MFAT) reveal concerns that Russia is registering its ships in the Cook Islands as part of its creation of a shadow fleet to avoid sanctions on the sale of its oil. Also called “dark fleet,” the vessels are normally oil tankers, named due to their practice of “going dark” by turning off trackers to obfuscate their movements. Maritime law requires that any ship on the high seas have a flag; otherwise, it’s considered a pirate. The country under whose flag a ship sails is responsible for safety and enforcing regulations on board. The complex ownership structures of these ships, designed to hide their true owners, means that shipping registries must be very well equipped to monitor them and have robust due diligence processes for registering vessels. They are usually old, poorly maintained, underinsured and do not meet international standards. The emails—released under the Official Information Act—also offer to help Maritime Cook Islands improve its standards since the problem is worsening despite the agency having all the information it needs to act against non-compliant vessels. Of particular concern to New Zealand at present is the Eagle S, a Cook Islands-flagged tanker that was seized by Finnish authorities on Christmas in 2024 in the Baltic Sea after it was believed to have severed the Estlink 2 submarine cable that carries electricity from Finland to Estonia. “Wellington has instructed us to demarche (officially inform) the Cook Islands on the issue of the shadow fleet, to reemphasise our concerns, seek assurances, and offer support to the Cook Islands,” says a Jan. 10 email from New Zealand’s High Commission in the Cook Islands. Another sent on the same day says, “New Zealand’s existing concerns about the Cook Islands shipping registry have increased” following the Estlink 2 incident. “As the vessel is suspected of being part of the Russian ’shadow fleet,' we seek clarity from the Cook Islands Government about its response to the incident given the seriousness of the issue and potential consequences. Currently available data indicates an increase in the number of sanctioned vessels on its registry,” it continues. It said New Zealand seeks “assurance that all sanctioned vessels have been formally deregistered or that action is currently underway to do so.” A document from the New Zealand/Cook Islands Joint Ministerial Forum Working Group and the Joint Defence and Security Dialogue reports that New Zealand officials “shared an update on New Zealand’s latest tranche of sanctions against Russia.” It notes they “emphasised our deep concerns about Russian and DPRK [North Korea’s] use of dark fleet vessels to transport oil in contravention of the G7+ Oil Price Cap, and in breach of likeminded partners’ sanctions regime. “We underlined our concerns regarding the Cook Islands registry registering vessels associated with the shadow fleet and undertook to provide information soon on Cook Islands-flagged vessels we suspect were doing dark fleet activities. (Comment: This was since provided ... on Dec. 6).” New Zealand’s sanctions, it noted, “are aimed at individuals connected to chemical weapons and ballistic missiles. New Zealand had now sanctioned over 700 individuals and entities.” New Zealand’s post in Rarotonga, Cook Islands, was asked to convey the seriousness of the situation from an international relations, international security, potential liability, and reputational perspective. “The actions of Cook Islands flagged vessels, and any perceptions of lack of action or concern by the Cook Islands Government in response, could affect the Cook Islands’ international standing, and the efficacy of international sanctions efforts of like-minded countries,” it warned. “You should also make the point that the activities of dark fleet vessels directly undermine international security and therefore our shared security interests.” The Cook Islands claims it, and the privately-owned company, MCI, which maintains its registry, are committed to upholding international sanctions against Russia. But of the 59 vessels sanctioned to date, nine sail under the Cook Islands flag.