An operation to reduce the spread of tuberculosis in cattle cost £76,000 for each badger killed.

The bill to taxpayers in Wales totalled £383,112 for the exercise, in which five of the nocturnal mammals were culled on three farms last year.

Blood tests on the badgers provided differing results before and after death – prompting claims the money was wasted.

Vaccinating badgers, rather than culling them, 'brings landowners and animals together'

Culling on the three farms between August and November was part of the Welsh government’s attempts to reduce the spread of bovine TB in cattle herds with repeated outbreaks.

A total of 37 badgers were trapped and their blood was tested for the disease at the setts. Any that tested positive were killed – five in all, a Welsh government report has revealed.

But when the blood test was repeated in the laboratory after post-mortem examinations on the bodies, they tested negative, with no infection showing.

The costs of the trapping, blood tests and post-mortem examinations came to £383,112 – the equivalent of £76,622 for each badger killed.

Wildlife activists seized on the figures in the report to say that badger culling was a “costly distraction from dealing with the key causes of the spread of bovine TB”.

Rosie Woodroffe, of the Zoological Society of London and one of Britain’s leading experts on bovine TB and badgers, said the prevalence of infection was uncertain but the disease could have been present in five out of 37 or in none at all.

“Sounds like a rubbish blood test,” she said.

The Stop the Welsh Cull group called for an investigation by the public accounts committee for the bill that it said was 10 times the estimated cost.

The campaigners said: “Welsh taxpayers will be outraged. This report reveals that the policy is a shockingly costly failure and is yet more evidence that badgers are not to blame.

“Introducing accurate Actiphage testing [a new high-tech test] should be the urgent priority, alongside controlling slurry pollution and other mechanisms which spread infection among cattle and out into the environment.”

The Welsh government was forced to release the information on the culling trial after activists appealed to the Information Commissioner over its initial refusal.

Ministers in Cardiff have rejected a widespread cull like those being undertaken in England, where a judicial review is underway of the latest cull expansion.

Cull supporters argue that TB cannot be eradicated from cattle while badgers continue to pick it up and pass it on around farms through their urine and droppings.

The Badger Trust said the fact that infections could not be proven “sends out a very clear signal to the farming and livestock veterinary industry in Wales that any form of badger culling is a hugely costly distraction from dealing with the key causes of the spread of bovine TB in the cattle industry”.

The trust called for a return to vaccination to reduce bovine TB in badgers, which it said was caused by “industrial pollution from the intensive livestock industry”.

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A Welsh government spokesperson said: “Badgers are only trapped and tested where evidence suggests they are causing TB in chronic breakdown herds.

“Targeted interventions are being applied to limit the number of badgers removed, helping stop transmission and clearing up chronically infected herds, which are costly to the taxpayer and industry.”

He said the TB organism does not grow easily in the laboratory, so its absence post-mortem did not necessarily mean the animal did not have TB.