The world's deepest plastic bag has been found at the bottom of the Pacific Ocean's Mariana Trench, highlighting the spread of ocean pollution.

Scientists made the discovery at 36,000ft (10,898m) in the world's deepest ocean trench, one of 3,000 pieces of man-made debris dating back 30 years.

Numerous international teams working around the world on over 5,000 separate dives and using deep-sea remote vehicles helped study the ocean beds to discover what lies beneath.

Over a third of the debris found was micro-plastic, with 89 per cent from single-use products.

The full findings of the study have been published in the journal Marine Policy. It shows how human activities are now also affecting deep-sea ecosystems.