On November 6, the SPCA received an anonymous letter alleging animals had been mistreated at the farm between January and August 2011.
It alerted Sir Peter and the American Humane Association, which oversees animal welfare on films, and sent an SPCA inspector to the farm.
"There wasn't anything in the allegations," said SPCA national chief executive Robyn Kippenberger. "This is certainly not about the animals. If it had been about the animals someone would have come to us when it was happening, not months later. No one did."
A wrangler who spoke to the Herald on the condition of anonymity said the animals at the farm were treated "pretty well".
He worked there for more than a year alongside Mr Smythe and others making similar claims.
"I have seen what Peter Jackson has said about it and I support him."
The allegations prompted animal rights group People for the Ethical Treatment of Animals to organise protests at premieres of The Hobbit around the world.
The vet used by Sir Peter and the owner of the farm issued statements of support last night.
"We were consulted promptly in cases of injury and illness. We were also consulted routinely about ongoing veterinary care and preventative medicine," said vet Julia Bryce.
"At no time were we concerned about the welfare and ongoing treatment of animals under our care."
Farm owner Joy Gray was "appalled" to hear about the claims.
"[We] saw nothing to make us uncomfortable or give us cause for concern. In fact, the animals were wonderfully looked after, being well fed, well housed, and well treated. The 60 horses, the cattle, oxen, sheep, goats, dogs, pigs, hens were given professional and humane treatment."
Ms Kippenberger said Sir Peter had asked to meet her next year to discuss ways of ensuring claims like this could not hit filmmakers in the future. She said although the AHA oversaw animals on set, there was no monitoring system in New Zealand for areas where animals were trained or wrangled.
She was looking forward to discussing how such a system could be set up and suggested SPCA inspectors could play a role.
In a statement Sir Peter said the allegations were unsubstantiated.
"The production regrets that Peta has chosen to make such a serious accusation, which has distressed many of the dedicated Kiwis who worked with animals on the films - including trainers, wranglers, caregivers, farm workers and animal health care professionals - without properly vetting the source from which it received this information."
Film took great care: farm boss
The Glen in Pauatahanui is owned by Joy Gray and spans 720 hectares.
The Hobbit animals were all housed on the flat part of the farm, towards the front of the property.
Farm manager Ross Berry said he saw the animals every day and never noticed any signs of animal neglect or abuse and completely disputed what the animal wranglers claimed.
"I would not tolerate any cruelty on the farm in any shape or form," he said.
There were some deaths of animals on the farm, but he said that was no fault of the staff who stayed there.
"There wasn't any deaths through being malicious ... they were straight-out accidents. I have been very impressed with the way they [film staff] looked after everything."
At one stage a horse was foaling, so the workers hooked her up to a monitor so that when she lay down a buzzer would sound in Mr Berry's home to let him know the horse was about to give birth.
"They were so concerned."
Mr Berry said that whenever there was a problem, a vet was called at any hour and at any cost to the production company.
- APNZ
