Samantha Chandler, from the Anglican Society for the Welfare of Animals (ASWA), was speaking after American police announced their investigation into the incident would be focusing on the actions of the parents rather than claims of negligence by Cincinnati Zoo in Ohio.
Zookeepers there had to shoot dead the Western Lowland gorilla, called Harambe (below), in order to protect the child's life.
A Cincinnati police report says the boy fell 15 foot into Harambe's watering hole before the gorilla picked him up and carried him up into his treehut.
It initially appeared that Hadambe was protecting the boy, but staff at Cincinnati Zoo were forced to act after he began dragging him.
The boy suffered minor injuries.
Cincinnati Zoo Devastated by Death of Beloved Gorilla. https://t.co/7zxnWBRjTt pic.twitter.com/dBdzx5pKfL
— Cincinnati Zoo (@CincinnatiZoo) May 29, 2016
Cincinnati Zoo has said its gorilla enclosure is safe and a government inspection two months ago agreed.
However, there was an incident in March where polar bears were wandering inside a behind-the-scenes area.
Samantha Chandler told Premier's News Hour: "It's a very tragic story.
"I think the greatest tragedy of all is that Harambe was in the zoo in the first place. I don't believe wild animals should be incarcerated in this way."
"We really do have to have a very long, hard look at [whether it] is right to keep these big animals in such false, unnatural conditions.
"When we take these actions and we take animals out of their natural environment and keep them in totally alien environments, we're asking for trouble."
