Russia has built a "ghost fleet" of oil ships, by buying tankers to which it offers its own insurance services. The number of oil tankers with opaque ownership or without proper insurance has soared, experts say.

These ghost ships do not have adequate insurance, called “P&I”, which is mandatory for commercial ships to cover war risks, collisions or environmental damage. Some 90-95% of the P&I insurance market is in the hands of insurers from the European Union and the United Kingdom, which enforce the sanctions against Moscow.