The footage shows the dolphin being hosed down by its keepers, wrapped in mats and lifted back into the tank with a crane, while the other dolphins in the tank appear to be distressed and gather inside the tank where the creature leapt out.

Former US dolphin trainer turned campaigner, Rick O’Barry, 70, said the video showed a dolphin under stress.

“The habitat of that false killer whale is so unnatural it leaped out in desperation,” he said. “It wanted to end it. Why does a person jump out of a building?”

Hideshi Teruya, who manages the dolphin section at the park, said the mammal had suffered minor scratches and bruises on its head and fin, but had a healthy appetite for mackerel and squid after it was returned to the tank.

“It was playing around and jumped out by accident from the momentum,” he said.

The age of the dolphin, a female named Kuru, which means “black” in Okinawan dialect, is unknown. It was captured about six years ago in the seas around Okinawa, Mr Teruya said.

He acknowledged that the dolphins sometimes sprang out so he had placed mats around the tanks to prevent serious injury.

He denied the captivity was cruel, and said the tank was not overcrowded and followed general aquarium guidelines.

Mr O’Barry believes such guidelines are inadequate. Dolphins are used to roaming for many miles a day, not swimming in a circle and doing flips at shows, he said.

Sound is the most important sense for dolphins. So keeping them in a concrete box is cruel, bombarding the animal with strange sounds and depriving a key sensory skill, according to Mr O’Barry.

“It proves that captivity doesn’t work,” he said of the video. “They are free-ranging creatures with a very large brain. They’re self aware and putting them in a small tank in a stadium setting is abusive.”

Via Telegraph