Transport inspectors say they have turned away two ships from Dutch waters suspected of Russia’s sanctions-busting “shadow fleet”.

The Human Environment and Tranport Inspectorate (ILT) refused the ships access to the Westerschelde after stepping up its checks on incoming vessels.

The ILT uses a checklist to detect ships that are likely to be Russian vessels operating under other countries’ flags to avoid sanctions designed to stop Russia exporting oil via European ports.

Research by NRC in March uncovered a shadow fleet of around 1,600 container vessels, many of them old, in a poor state of repair and under-insured. The fleet accounts for an estimated one-tenth of the world’s oil tankers.

The ships transport crude oil to countries that have not imposed sanctions against Russia before attempting to refuel in North Sea ports on the way home – partly to take advantage of lower fuel prices.

The ILT and the Dutch-Belgian Joint Nautical Authority (GNA) check the ships for signs that they may be sailing under a false flag, such as whether the GPS tracking system has been switched off during the journey or any missing paperwork.

Two vessels have been refused entry to the Westerschelde in recent months and there are signs that other vessels have been avoiding the area since the stricter checks were imposed.

“It’s not a break in the trend, but there has been a slight fall-off in the number of ships wanting to drop anchor in the Westerschelde,” George Jaburg, chair of the Vlissingen boathouse association, told Omroep Zeeland.