The parents of the boy who fell into a gorilla enclosure - resulting in the death of 17-year-old silverback Harambe - have been issued with death threats.

Staff at the zoo in Cincinatti, Ohio, shot the endangered primate fearing four-year-old boy Isaiah's life was at risk.

Now couple Michelle Gregg, 32, and Deonne Dickerson, 37, have been blasted by those angry at the endangered animal's tragic death.

One Twitter user wrote: "How about blaming the f*****g numb-nut parents. Shoot them not the Gorilla."

"I'm pro animals. Take better care of your 3yr old F*****G KID you lazy son of a b***h. Shoot the parents first then the gorilla. Rant over," wrote on furious tweeter.

Another said: "Feel for the gorilla. Didn't deserve to get shot. Shoot the s****y mum instead."

The couple, who reportedly have four children together, are now facing neglect charges over the incident in Cincinnati, Ohio.

Deonne Dickerson and Michelle Gregg - the parents of the four-year-old boy

Reporters outside the couple's Ohio home were turned away politely, with the family even said to have turned down a big money offer from a New York breakfast show as they shield themselves from the massive social media backlash.

According to police reports, the father has a lengthy criminal history spanning years with charges including burglary, firearms offences, drug trafficking, criminal trespass and kidnap.

Deonne Dickerson, the parent of the four-year-old boy who fell into the gorilla enclosure at Cincinnati Zoo

Harambe, a 17-year-old gorilla at the Cincinnati Zoo

Harambe was 17-years-old gorilla when he died

But Dickerson appears to have made a remarkable turnaround in recent years – with frequent posts on Facebook showing updates of his children and working life, Daily Mail Online reports.

The industrial worker was also congratulated by friends last January when he had his fourth child with Deonne.

She is an administrator at a Cincinnati pre-school and has faced heavy criticism after attempting to defend what happened by claiming that “accidents can happen”.

Gorilla death reaction on twitter Staff at the zoo in Cincinatti, Ohio, shot the endangered primate fearing the child’s life was at risk

New footage emerged last night that appeared to show the “gentle giant” protecting the child rather than posing any threat.

Responding on Facebook shortly after the incident, Michelle said: "I want to thank everyone for their thoughts and prayers today. What started off as a wonderful day turned into a scary one.

Cincinnati Zoo Gorilla enclosure graphic

"For those of you that have seen the news or been on social media that was my son that fell in the gorilla exhibit at the zoo. God protected my child until the authorities were able to get to him.

"My son is safe and was able to walk away with a concussion and a few scrapes... no broken bones or internal injuries.

"As a society we are quick to judge how a parent could take their eyes off of their child and if anyone knows me I keep a tight watch on my kids.

"Accidents happen but I am thankful that the right people were in the right place today."

Zookeeper Jack Hanna backed the zoo's decision.

He said "I've seen him (Harambe) take a green coconut, which you can't bust open with a sledgehammer and squish it" he told "Good Morning America."

Thane Maynard, the zoo's director, stood by the decision to shoot the gorilla after he dragged the boy around by the ankle.

He said the ape was not simply endangering the child but actually hurting him.

"Looking back, we would make the same decision," he said.

gorilla world map Cincinnati Zoo The location of Gorilla World at Cincinnati Zoo

"The gorilla was clearly agitated. The gorilla was clearly disoriented," said Maynard, while lamenting the loss of "an incredibly magnificent animal."

He also denied claims the zoo has been negligent.

"The barriers are safe. The barriers exceed any required protocols,"Maynard said at a news conference about the incident on Saturday.

"The trouble with barriers is that whatever the barrier some people can get past it.. No, the zoo is not negligent," he said.

"The gorilla was clearly agitated. The gorilla was clearly disoriented," said Maynard, while lamenting the loss of "an incredibly magnificent animal."

He also denied claims the zoo has been negligent.

"The barriers are safe. The barriers exceed any required protocols,"Maynard said at a news conference about the incident on Saturday.

"The trouble with barriers is that whatever the barrier some people can get past it.. No, the zoo is not negligent," he said.

Harambe the gorilla as a baby at Gladys Porter Zoo before being relocated to Cincinnati Zoo Harambe as a baby at Gladys Porter Zoo before being relocated

The zoo received thousands of messages of sympathy and support from around the world, he said.

But Ian Redmond, Chairman of The Gorilla Organization, said keepers had other options besides a fatal shot.

He told CNN: “When gorilla or other apes have things they shouldn’t have, keepers will negotiate with them, bring food, their favourite treats, pineapple or some kind of fruit that they don’t know.