The director of a documentary on Harambe says the zoo made a critical mistake which could have prevented the gorilla from being killed.
Harambe, a 17-year-old Western lowland gorilla, was shot and killed by Cincinnati Zoo staff in Ohio, US, in 2016.
A three-year-old boy fell into his enclosure through a barrier and dropped approximately 15 feet down into the gorilla's area.
When Harambe approached the child and interacted with him, he appeared to drag the boy.
That's when zoo officials made the decision to shoot Harambe rather than tranquillise him.
Although the child was rescued without significant injuries, critics argued that there was no need to kill the gorilla.
Filmmaker Erik Crown - who released the Harambe documentary in 2023 - has since explained why the zoo made that decision.
"Actually it's very important that they did not use a tranquilliser because tranquillisers don't work the way people think of in movies," he told UnchainedTV.
Harambe was shot and killed by Cincinnati Zoo staff in 2016 (Harambemovie.com)
"You don't fire tranquilliser dart and somebody goes down.
"It actually puts a system into overdrive which then shuts the system down it could take up to 20, 25 minutes to become active inside especially inside of a large gorilla.
"So that may have agitated Harambe and may have led to a different outcome, or a very dangerous outcome for the boy.
"So as much as we would have like to have seen a non-lethal ending to it, I don't believe the zookeepers necessarily had a choice with the way their program runs.
"And that is exactly why we feel we should not have endangered animals in captivity anymore."
However, Crown went on to reveal that the zoo 'was not in compliance' with adequate safety guidelines.
The director of a documentary on Harambe says the zoo made a critical mistake (Harambemovie.com)
"Now, what we uncovered while making the movie is that the zoo actually was not in compliance, their fence was not proper size," he said.
"And as a matter of fact it was it was a little under three feet tall and it was three simple wires that the kid climbed right under.
"Now, there is a lot of question marks as to what were the parents doing, but we did posit a similar question in response, which is when you take your children to a zoo or a movie theatre, for example, someplace where there is a public place that is allowed to have children, you do expect a certain level of safety.
"And the zoo failed and that's why the zoo was actually charged, penalised, and we spoke to some of the responding officers who didn't want to be in the movie, but they did an investigation and found no negligence on the mom's part.
"But what we did see at the end was a spam where everybody took their anger and it went directly to the parents and instead of the zoo who was legally responsible."
The documentary is now available to stream on Amazon Prime in the UK.