Sir David Attenborough has criticised Bear Grylls over the killing of animals on his TV shows.

Grylls’ Channel 4 shows have seen contestants slaughter caiman crocodiles and pigs in recent series, in scenes which have come under fire from viewers and animal welfare groups.

Sir David, 91, told The Sun: “We’ve never killed an animal. Bear Grylls will have to answer for himself.

“But I wouldn’t willingly kill an animal just to get a shot.”

Bear Grylls (Yui Mok/PA)Bear Grylls (Yui Mok/PA)

A scene on Grylls’ show Celebrity Island saw Olympic runner Iwan Thomas and soap star Ryan Thomas kill a caiman crocodile for food, after not eating properly for days.

The scenes proved to be distressing for some viewers, who said on social media that it was “cruel” and “disgusting” to kill an animal for TV.

In 2015, Channel 4 was accused of “killing animals to boost ratings” after contestants slashed the throat of a pig on The Island With Bear Grylls.

The scenes sparked nearly 500 complaints from viewers.