A 180 kilogram male gorilla in a US zoo has been shot dead after grabbing a three-year-old boy who fell into the ape exhibit moat.

Authorities said the boy, who fell three to four metres, is expected to recover after being picked up out of the moat and dragged by the 17-year-old gorilla for about 10 minutes.

• Australia’s oldest platypus found in Melbourne
• Baby gorilla delivered via rare emergency caesarean
• Orangutans learn to play video games at Melb Zoo

Watch the dramatic moments here:

Cincinnati Zoo Director Thane Maynard said on Saturday the zoo’s dangerous animal response team decided the boy was in “a life-threatening situation” and the gorilla named Harambe needed to be put down.

“They made a tough choice and they made the right choice because they saved that little boy’s life,” Maynard said. “It could have been very bad.”

Maynard said he hadn’t talked with the boy’s parents yet.

He said the gorilla didn’t appear to be attacking the child, but he said it was “an extremely strong” animal in an agitated situation.

He said tranquilising the gorilla wouldn’t have knocked it out immediately, leaving the boy in danger.

Maynard said it was the first time that the team had killed a zoo animal in such an emergency situation, and he called it “a very sad day” at the zoo.

The lowland gorilla is an endangered species.