Arctic sea ice contains a huge amount of microplastics which will be released into the world’s oceans with global warming, researchers have warned.

The Alfred Wegener Institute in Germany surveyed five regions in the Arctic Ocean and found there was 12,000 microplastic particles per litre of ice.

Analysis of ocean currents showed much of the debris had flowed from the Great Pacific Garbage Patch, the largest accumulation of ocean plastic in the world, which is situated between California and Hawaii.

Commenting on the study, British experts said it showed that the garbage patch, was ‘literally the tip of the iceberg.’

Researchers warned that not only is the microplastic dangerous for arctic wildlife, who eat it, but global warming could allow huge amounts to be released back into the world’s oceans.

“During our work, we realised that more than half of the microplastic particles trapped in the ice were less than a twentieth of a millimetre wide, which means they could easily be ingested by arctic microorganisms,” said biologist and first author Dr Ilka Peeken.

“No one can say for certain how harmful these tiny plastic particles are for marine life, or ultimately also for human beings.”