An expedition to a remote jungle has discovered a new species of rat, which is as big as a domestic cat.

The BBC Natural History Unit were filming in a Papua New Guinea rainforest when they came across the Bosavi Woolly Rat which measures over 80cm long an weights 1.5kg.

It is silvery grey in colour and got the name woolly is due to its dense fur. Experts say the animal's teeth suggest it has a largely vegetarian diet.

They say the rat - found in the crater of Mount Bosavi - probably builds nests in either tree hollows or underground but is related to the same kind you'd find in the city sewers.

Because the rat has had no previous contact with humans, it was not scared of the crew … the same couldn't be said the other way around.