It has been revealed that up to one million litres of crude oil has leaked out of a BP pipeline in the North Slope region of Alaska.
The spill covers about one hectare of the snow-covered tundra in the sparsely populated region on Alaska's north coast.
It is located some 1,000 kilometres north of the state's biggest city, Anchorage.
The leak was discovered last week and is believed to have been caused by internal corrosion in the pipe.
Environmentalists have described it as a catastrophe.
