Bear Grylls faces criticism from that last person you’d ever want to be scolded by: Sir David Attenborough.

The adventurer is under fire for Channel 4’s The Island, a reality show which has televised contestants killing caiman crocodiles, pigs, and turkeys as part of the show’s survival challenges.

Attenborough 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.”

The show has faced heavy criticism from both viewers and animal welfare groups. During last year’s celebrity spin-off of the show, Made in Chelsea star Ollie Locke, encouraged by fellow contestant Karen Danczuk, jumped on the back of a crocodile before stabbing it through the back of its neck.

At the time, Alan Knight, of International Animal Rescue, said of the incident, “I feel it is totally unacceptable to kill or abuse animals for entertainment.” The charity spokesperson claimed the animal “suffered unncecessarily”, as Locke would not have the right knowledge to kill the animal “humanely”.

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However, Channel 4 responded to the incident with: “The premise of the series, in aid of Stand Up to Cancer, is to see if when stripped of all the conveniences of modern life, celebrities have what it takes to survive and feeding themselves is a fundamental part of this. Those on the island all received training on how to kill animals humanely and this was utilised properly in each instance.”

The show had also been criticised in the past after male contestants on the show accidentally killed and ate a rare species of crocodile, killing an American crocodile while mistaking it for a common caiman.