A shadow fleet of old and poorly maintained ships is cruising the high seas, often hiding their true identities through a series of shell companies.

Their numbers have grown massively since Russia’s full-scale invasion of Ukraine.

Lloyd’s List estimates as many as 12% of tankers are part of the dark fleet.

There’s increasing concern about the danger to the environment, and to ship’s crews. But how effective at tackling the problem is the regulator, the International Maritime Organisation?

Presenter: Lesley Curwen Producer: Clare Williamson

(Image: Sea and ship at sunset. Credit: Getty Images)