Beyond the occasional shriek from a pointing child, the crocodile enclosure at Johnsons Zoo is normally a place of calm.

Something about these prehistoric beasts demands reverence and tends to make visitors emit tiny gasps of awe and speak in cathedral tones.

It was like this at lunchtime on Thursday as small groups filed along an elevated walkway in a converted cattle barn, peering over a metal barrier (not unlike the kind that separate crowds from red-carpet celebrities) down at the pit 15ft below.

But at just after 1pm something happened at the zoo near Huntingdon in Cambridgeshire that had the effect of contracting time and suspending the present. Something unusually horrifying.

Suddenly, a boy of three was in the enclosure’s shallow pool. What’s more, the crocodiles he had been eyeing excitedly moments earlier were now eyeing him and slithering through tropical vegetation in his direction.

Forget every parent’s nightmare – who would include this among the litany of their worst fears?

Some who were there recalled a fleeting sense of dislocating confusion. What were they seeing exactly? How could a child have fallen? It didn’t seem possible.

It was by no means immediately apparent, not to everyone, that the toddler hadn’t fallen. The reality was darker still. A man with learning difficulties is alleged to have picked him up and thrown him over the 4ft barrier. It is thought the toddler landed on concrete before rolling into the water.

Pictured: Johnson’s of Old Hurst, the crocodile farm in Cambridgeshire where a boy, three, was left in critical condition after being mauled by a crocodile (File image)

Zoo owner Andy and wife Tracey are pictured transporting a 400lb crocodile in 2009

All at once, silent disbelief gave way to sounds of panic. A punchy cry. A prolonged, high-pitched wail that one witness said, ‘We’ll never forget’. Desperate entreaties for someone to do something. And fast. By now this was turning into a horror show. One or more of the crocodiles was beginning to attack the child.

Mercifully, someone did do something. Zoo owner Andrew Johnson’s wife Tracey, who had celebrated the birth of her first grandchild days earlier, sprang into action.

Without hesitation, 55-year-old Mrs Johnson – whom one friend described yesterday as a ‘special, steadfast, old-fashioned heroine’ – climbed into the pen, waded to the boy and ‘swooped down to pull him to safety’.

She is then thought to have escaped through a keepers’ exit.

Chris Newman, director of the National Centre for Reptile Welfare, said: ‘Her actions are nothing less than what I would expect of her. She is an incredible lady. It was a very brave thing to do.’

Yesterday, the boy was in a critical but stable condition at Addenbrooke’s Hospital in Cambridge. Among his injuries are thought to be a broken arm and pelvis.

A 30-year-old man arrested at the scene, meanwhile, was released on bail until September 18 after being assessed as ‘not fit for interview’.

It is thought he was on an organised trip with other vulnerable adults and at least two carers.

Pictured: A crocodile in its enclosure at the Johnsons of Old Hurst zoo in Cambridgeshire

Questions about their supervision – and whether the zoo was an appropriate place to visit – are likely to be hastily addressed. A local said: ‘The carer apparently wasn’t watching him at the time.’

Mr Newman said he was unaware at first that Mrs Johnson had risked her life. After he learned of her rescue mission, he messaged her to ‘make sure she was OK and had not been injured in any way’.

He added: ‘She is fine…I know the zoo very well. I have been there many times.

‘It is a fantastic site where safety is of the utmost importance.’

Neither Andrew nor Tracey, who have grown-up twin sons, are under any illusions as to the dangers posed by the crocodiles. Not for them a special keeper-animal rapport. It doesn’t work with these creatures. In jest, though, they’ve given them cutesy names such as Cuddles and Romeo.

The threat is laid bare on the zoo’s website, which talks of the reptiles’ ‘stealth and precision’ and ‘lightning-fast reflexes’ and how they seize prey with jaw-dropping speed. ‘Their surprising agility can catch even seasoned keepers off guard,’ it says.

In other words, the boy’s rescue was little short of miraculous.

Yesterday, Mrs Johnson was seen at the zoo looking contemplative and clutching a bunch of flowers. The first of many, no doubt.

Another friend of hers, who gave her name as Kally, said Mrs Johnson would not have thought twice about putting herself in danger to save a child. ‘Tracey and Andy must be going through hell right now,’ she added.

‘They have just become grandparents and have their first grandchild. So I’m sure they are feeling for the parents and that little boy. I have known them for years. I couldn’t think of anything bad to say about them. They just help everybody. They are selfless.’

Mr Johnson first became fascinated with crocodilians during a trip to Florida and adopted several from a private collector.

The zoo now is said to have a collection of around 50 crocodiles and alligators, which are mainly used as an environmentally friendly way of getting rid of dead livestock. Its tropical house, a converted barn, is home to American alligators, broad-snouted caiman, Cuvier’s dwarf caiman, Morelet’s crocodile, Nile crocodile, saltwater crocodile, Siamese crocodile, spectacled caiman and West African dwarf crocodile.

The largest of these species is the saltwater crocodile, which is found between India and Australia, and can grow up to 20ft long and weigh 3,300lb – the weight of a Ford Focus. Mr Johnson once said: ‘The best way to build trust with them is not to stand up and look like you’re the dominant person, but to get down to their level and work with them.’

Johnsons, as it is known, describes itself as a farming business with a butcher, farm shop, tearoom, steakhouse and the zoo in the village of Old Hurst.

When it opened as a crocodile farm 20 years ago it was viewed as a curiosity. It seemed incongruous to some that such exotic creatures should be bred in the heart of England – in a village, in fact, through which Oliver Cromwell, who lived at Huntingdon, would regularly travel as a young man.

Still, locals raised no objections and Huntingdonshire District Council granted Mr Johnson a licence to keep the animals under the Dangerous Wild Animals Act.

Andrew Johnson of Johnsons of Old Hurst where they have a tropical enclosure which houses crocodiles, snakes and other creatures

At the time, Mr Johnson said he was ‘wary’ of them, having been bitten by a small crocodile. ‘We are learning by trial and error,’ he said. ‘The main thing is you must never lose eye contact with them.’

Yesterday, the zoo said in a statement: ‘Our thoughts and prayers are with the boy and his family. Out of respect to the family, our tropical house will remain closed until further notice. The rest of the site will remain open.’

Charlotte Lowe, 52, a district and county councillor who lives nearby, said the zoo had ‘a very good reputation’ locally and that the owner was regarded as ‘a pillar of the community’.

She said she had always felt safe at the zoo, adding: ‘They’ve got all the right protection. I just don’t know how it would have happened. This is just awful.’

In 2021 the zoo featured in ITV’s Britain’s Tiger Kings: On The Trail With Ross Kemp. And only a few months ago the rapper Fekky included the zoo on his YouTube show, Hood 2 Farm, in which he meets other farmers.

The musician moved from South London to Cambridgeshire after lockdown.

In his film, Mr Johnson shows him around the same enclosure in which the boy was attacked and, indicating his elbow, warns jokingly that a crocodile ‘would have your hand up to here’.

While feeding the crocodiles, Mr Johnson warns Fekky: ‘That’s the difference with an alligator, you can trust them.’

Fekky responds: ‘The crocodile? They can come for me? They think I’m the bigger meal, innit?’

Johnson responds: ‘Yeah! They’d have your hand up to here.’

In another YouTube video, Mr Johnson says he handles the crocodiles using a ‘pig board’ – a handheld barrier or shield used by farmers to move pigs.

In the film, he is inside the crocodile enclosure, perched on a large log with his elbows on his knees and leaning forward.

Police at Johnsons of Old Hurst, in Huntingdon, where the three-year-old boy was taken to hospital with serious injuries on Thursday after ending up in the crocodile enclosure

‘When we’re handling the crocs, the main thing we use is a pig board, and the idea is if you’re sitting like this [he moves the board to the side and slaps his leg, showing he’s exposed] he’ll grab your leg and drag you in. And just having the board in front takes away the striking point, the grip point, and they don’t bother.’

Detective Inspector Verity McCann, of Cambridgeshire Police, said yesterday: ‘Our inquiries are ongoing as we continue to understand the circumstances surrounding this distressing incident. Our thoughts remain with the boy and his family, and specialist officers continue to support them through this difficult time.’

The incident has chilling echoes of an incident at the Tate Modern art gallery in London in 2019 when a six-year-old French tourist was hurled from an outdoor viewing platform. Although he survived the 100ft fall, he received life-changing injuries.

Autistic 17-year-old Jonty Bravery was jailed for life with a minimum term of 15 years in 2020 for attempted murder, and is being held at Broadmoor high-security psychiatric hospital in Berkshire.

Additional reporting: Olivia Christie and Martin Robinson