The Veterinary Laboratories Agency in Britain this week said an atypical, or unusual, form of scrapie had been detected in a 6-year-old cheviot ewe.

For research purposes, the Department for Environment, Food and Rural Affairs (DEFRA) maintains a flock of sheep that are believed to be free of Transmissible Spongiform Encephalopathies (TSEs) as all the founder animals in the flock were imported from New Zealand, a country considered to be free of TSEs. The flock is managed under strict bio-security conditions to insure that the animals do not come into contact with other sheep.

As the origin of the atypical scrapie in this case is not clear, this finding will now be subject to independent scientific investigations, which will include ensuring that the bio-security on the farm was not compromised and that there was no possibility of cross contamination of the sample.

Biosecurity New Zealand head, Barry O'Neill, said they were co-operating closely with British authorities. New Zealand had not identified atypical scrapie or classical scrapie, he said.

Biosecurity was focused on trying to clarify the origin of the source flocks which were exported to the United Kingdom in the late 1990s.

"We're unsure at this stage if they exist, but if they do exist, we would wish to undertake some surveillance testing over the future weeks and months to identify if there is any remote possibility that sheep from these flocks could be involved," stated O'Neill.