A team of scientists drawn from the US, Norway and Hong Kong and headed by marine biologist Tim Gordon of Exeter University in the UK found polystyrene chunks 1,609 kilometers from the North Pole in the area that was previously inaccessible because of sea ice.

They found two large pieces on the edge of ice flows between 77 degree and 80 degree north, in the middle of the international waters of the central Arctic Ocean.

It is one of the most northerly sightings of such debris in the world's oceans, which are increasingly polluted by plastics and confirm just how far plastic pollution has spread, 'The Guradian' reported.

The finding has prompted fears that as the ice melts, because of climate change, plastic that has long been trapped in it is flowing into the Arctic.

"Finding pieces of rubbish like this is a worrying sign that melting ice may be allowing high levels of pollution to drift into these areas," said Gordon.

"This is potentially very dangerous for the Arctic's wildlife," he said.

More than five trillion pieces of plastic are estimated floating on the surface of the world's oceans. It has been claimed that there is now enough plastic to form a permanent layer in the fossil record.

A significant concern is that large plastic pieces can break down into "micro plastics" tiny particles that are accidentally consumed by filter-feeding animals.

The particles remain in animals' bodies and are passed up the food chain, threatening wildlife at all levels from zooplankton to apex predators such as polar bears, researchers said.

"Many rivers that are often a source of plastic pollution lead into the Arctic Ocean, but plastic pollution has been literally trapped into the ice. Now the ice is melting we believe microplastics are being released into the Arctic," said Ceri Lewis from University of Exeter.

Some projections indicate that the entire Arctic Ocean will be ice-free in summer by 2050, allowing human exploitation such as commercial fishing, shipping and industry of the newly opened waters.