COPENHAGEN -- Norwegian zoologists have found about 30 plastic bags and other plastic waste in the stomach of a beaked whale that had beached on a southwestern Norway coast.

The visibly sick, 2-ton goose-beaked whale was euthanized, Terje Lislevand of Bergen University said Friday.

"The (whale's) stomach was full of plastic," Lislevand said, adding that its intestine "had no food, only some remnants of a squid's head in addition to a thin fat layer."

Lislevand says the non-biodegradable waste was "probably the reason" why the male whale repeatedly beached last Saturday in shallow waters off Sotra, an island west of Bergen, 200 kilometres (125 miles) northwest of the capital of Oslo.

It size -- about 6 metres (20 feet) -- showed the whale was an adult.

The UN estimates that 8 million tons of plastic trash are dumped into the world's oceans each year, he said.