North Koreans have been forced to work on Chinese-flagged fishing vessels without touching land for as long as a decade, facing verbal and physical abuse as well as harsh conditions, a report found.

Pyongyang has long made a fortune from an army of citizens it sends abroad to work, mostly in neighbouring China and Russia.

A 2017 UN Security Council resolution, supported by China, required countries to deport North Korean workers to prevent them earning foreign currency for Pyongyang’s nuclear and ballistic missile programmes.

But analysts have accused Beijing and Moscow of circumventing the measures.

And the report published by the London-based Environmental Justice Foundation (EJF) alleges widespread abuse of North Korean workers at sea, in violation of sanctions.

The report said: “North Koreans onboard were forced to work for as many as 10 years at sea –in some instances without ever stepping foot on land.

“This would constitute forced labour of a magnitude that surpasses much of that witnessed in a global fishing industry already replete with abuse.”