2026年6月15日，英国皇家海军陆战队与国家犯罪局（NCA）联合行动，在英吉利海峡登临并扣押了一艘悬挂喀麦隆国旗的油轮MV Smyrtos，该船被指控为俄罗斯”影子舰队”的一部分，运输受制裁的俄罗斯石油。船长Ajay Pant（38岁，印度籍）被指控违反《俄罗斯制裁条例（欧盟退出）2019》，最高面临10年监禁。这是英国首次针对影子舰队进行刑事起诉，标志着西方对俄制裁执法力度的显著升级。
本次扣押行动的法律依据主要来自三层规范：首先，依据《联合国海洋法公约》（UNCLOS）第110条规定的登临权（right of visit），英国作为船旗国在怀疑船只从事非法活动时享有登临检查的权利；其次，英国《俄罗斯制裁条例（欧盟退出）2019》作为国内法实施了对俄贸易禁令与制裁措施；最后，英国首相于2026年3月授权的制裁与海事执法权限为本次联合行动提供了权力基础。
本次行动引发的核心争议在于制裁执法的法律边界。一方面，英国主张影子舰队的存在破坏了国际制裁体系的完整性，使俄罗斯得以绕过制裁继续通过能源出口获取战争资金；另一方面，法律学者质疑针对悬挂第三国旗帜、船长为第三国国民的船舶进行刑事起诉是否符合国际法中罪刑法定原则与主权豁免原则。特别是，当英国当局声称”影子舰队规模自2022年以来增长了三倍”时，却未明确指出MV Smyrtos具体违反了哪一项明确列明的制裁清单，这可能引发执法标准模糊化的担忧。
此次扣押释放了一个明确信号：西方制裁已从”经济威慑”转向”刑事执法”。对于国际航运业而言，这意味着运输俄罗斯能源的风险不再是经济损失，而是船东与船员面临刑事指控的可能。从合规角度，航运公司需要建立更为严格的制裁筛查机制，不仅在合同层面排除涉俄货物，还要在实操层面确保船舶航行路线、保险安排、船员资质等各环节均不触及制裁红线。
UK’s First Detention of Russian Shadow Fleet Tanker: Legal Boundaries of Sanctions Enforcement
On June 15, 2026, British Royal Marine Commandos and the National Crime Agency (NCA) conducted a joint operation to board and detain MV Smyrtos, a tanker flying the Cameroonian flag, in the English Channel. The vessel was accused of being part of Russia’s “shadow fleet” transporting sanctioned Russian oil. Captain Ajay Pant, a 38-year-old Indian national, was charged with violating the Russia (Sanctions) (EU Exit) Regulations 2019, facing up to 10 years’ imprisonment. This marks the UK’s first criminal prosecution against the shadow fleet, signifying a significant escalation in Western sanctions enforcement against Russia.
The legal basis for this detention operation stems from three layers of norms: First, under Article 110 of the United Nations Convention on the Law of the Sea (UNCLOS), the right of visit, the UK as a flag state enjoys the right to board and inspect vessels suspected of engaging in illegal activities; Second, the UK’s Russia (Sanctions) (EU Exit) Regulations 2019 implements domestic trade embargoes and sanctions against Russia; Finally, the sanctions and maritime enforcement powers authorized by the UK Prime Minister in March 2026 provide the power basis for this joint operation.
The core controversy triggered by this action lies in the legal boundaries of sanctions enforcement. On one hand, the UK claims that the existence of the shadow fleet undermines the integrity of the international sanctions regime, allowing Russia to continue obtaining war funds through energy exports while circumventing sanctions. On the other hand, legal scholars question whether criminal prosecution against vessels flying third-country flags with captains of third-party nationalities conforms to the principle of legality in international law and sovereign immunity principles. In particular, when British authorities claim that “the shadow fleet has tripled in size since 2022,” they fail to explicitly specify which clearly listed sanctions schedule MV Smyrtos violated, which may raise concerns about the vagueness of enforcement standards.