The BBC has denied misleading Frozen Planet viewers with footage of newborn polar bear cubs filmed in an animal park, rather than in the wild.

Episode five of the series featured the cubs in a den with their mother, with many people assuming they were born and filmed in the Arctic.

Speaking to Radio 5 Live, executive producer Alastair Fothergill said the decision to film in captivity was made because it is "impossible to film inside a polar bear den in the wild".

Mr Fothergill added: "These wonderful early moments in the lives of a polar bear are very special - that's why we decided to do it in captivity."

Footage courtesy of BBC's Frozen Planet.

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Victoria Derbyshire broadcasts weekdays 1000 to 1200 on Radio 5 live.