A three-year-old boy critically injured in a zoo enclosure was attacked by a crocodile, police have confirmed.
Cambridgeshire Police said a 30-year-old man arrested on suspicion of attempted murder following the incident had now been bailed and was "unfit for interview".
The boy was attacked by at least one crocodile after ending up in the enclosure, the BBC understands.
He remains in a critical but stable condition after being injured at Johnsons of Old Hurst, near Huntingdon, Cambridgeshire, on Thursday.
Police said the boy sustained serious injuries "while in the enclosure" and was pulled out by zoo staff.
He received medical treatment at the scene before being taken to Addenbrooke's Hospital in Cambridge.
Officers said they were working to establish how long the boy, from Cambridgeshire, was in the enclosure.
Police said the crocodiles had not been seized or killed.
Det Insp Verity McCann said: "Our enquiries 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 man who was arrested was from Norfolk, police said.
People may be considered not fit to be interviewed because of their physical or mental state.
A spokesperson for Johnsons said on Thursday its thoughts and prayers were with the boy and his family.
They added the site's Tropical House, which contains the crocodile enclosure, had been closed "out of respect to the family".
Zoo staff were seen arriving at the site earlier and it is due to open at 10:00.
Crocodiles first arrived on the family-run farm in 2006.
They are kept in a converted cattle barn, which has metal-fenced elevated walkways looking down on large pools of water surrounded by tropical vegetation.
To celebrate the 20th anniversary of the first farm shop, a new museum at the site was due to open with a special weekend event starting on Saturday. It is unclear if the opening will go ahead.
On Thursday, police said they were speaking to people who were at the zoo at the time of the incident.
"We do not believe the man arrested and the child are known to each other," a police spokesperson said.
Huntingdon MP Ben Obese-Jecty urged people to "refrain from speculation online" and said police were treating it as a "critical incident".
A Magpas Air Ambulance spokesperson said a critical care team attended the incident at 13:42 and "treated one patient at the scene before taking them to hospital".
According to its website, Johnsons of Old Hurst is a farming business that now features a butchers, a farm shop, tea room, steakhouse and zoo.
It says it "houses over 100 fascinating animals" including crocodiles, African lions and a Bengal tiger.
