An investigation by The British Wire has found that a 'ghost fleet' of hundreds of ageing oil tankers, often operating with obscured ownership and fraudulent insurance, is still being facilitated by several minor ship-broking firms in the City of London.

The fleet is used to transport sanctioned oil across the globe, bypassing international restrictions and posing a massive environmental risk due to the poor condition of the vessels. The findings raise serious questions about the enforcement of UK sanctions in the maritime sector.

"The paper trail leads directly to the heart of London," said a former sanctions enforcer.