An alpaca called Geronimo, which twice tested positive for bovine tuberculosis, will have to be slaughtered, the High Court has ruled.
The animal's owner had been appealing to save him, believing the tests were returning false positives.
Helen Macdonald has been refused permission to have the animal tested a third time - but the court concluded there was "no prospect" of success in her bid to overturn an earlier ruling.
The Department for Environment, Food and Rural Affairs (Defra) says she will not have to destroy Geronimo today.
Speaking after today's ruling Ms Mcdonald said she was "really quite shocked" at the outcome but that "it's not over".
Ms Macdonald lost her final appeal at the High Court earlier this month and a warrant was issued for the alpaca to be euthanised.
More than 130,000 people signed a petition calling on the prime minister to halt the killing, which has sparked a public outcry.
Ms Macdonald, who owns a farm at Wickwar in South Gloucestershire, imported Geronimo from New Zealand in 2017.
An application for an injunction to stop the destruction order was considered by the High Court yesterday - but the judge said she needed more information from Ms Macdonald and from governiment lawyers before she could make her decision.
The hearing was adjourned until today, when Mrs Justice Stacey refused the application.
Geronimo first tested positive for bovine tuberculosis in September 2017 and has been in isolation ever since, according to the owner's lawyers.
Catrin McGahey QC said nine other animals who were subject to the same testing regime as Geronimo showed no signs of the disease after they were slaughtered, indicating a potential flaw in the tests.
She argued that Defra knew about this and had not disclosed the information, which came to light as a result of a recent Daily Mail investigation.
Mrs Justice Stacey said the farmer's complaint about non-disclosure was a "disingenuous and backdoor way of seeking a further route to appeal" and did not give rise to an arguable case.
Ms Macdonald told the PA news agency: "I thought that the judge would allow the evidence to be put forward so that we could look at it."
She said the judge seems to have taken it "on face value" that Defra have disclosed what they needed to disclose.
"Clearly they haven't, because they've been covering this up for four years," she said.
She added: "It's not over. We're back to where we were a week ago."
She said the government has to "sort this out properly", adding: "I'm not having my healthy animal put to sleep, and neither am I going to permit them, if I can possibly help it, to come and slaughter him in front of the rest of the planet.
"They seem to want to make it my decision, and make me put my animal to sleep, to get the blood off their hands. I'm not doing it."
Dr Iain McGill, a vet who has been advising Geronimo's owner, said the decision made at the High Court was "incredible".
He said Defra has been "unable to produce any evidence" to back up claims that the tests used on Geronimo are over 99% accurate.
"Geronimo's diagnosis is more than unsafe," he said. "It is a miscarriage of justice."
Ned Westaway, representing Defra executive agency the Animal and Plant Health Agency, said Ms Macdonald would be given the opportunity to make her own arrangements for Geronimo's destruction.
The government has insisted the testing results and options for Geronimo have been carefully considered.
A Defra spokesperson said: "Bovine tuberculosis is one of the greatest animal health threats we face today and causes devastation and distress for farming families and rural communities across the country, while costing the taxpayer around £100 million every year.
"Therefore, while nobody wants to cull infected animals, we need to do everything we can to tackle this disease to stop it spreading and to protect the livelihoods of those affected."
© Sky News 2021
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