MAF Biosecurity New Zealand (MAFBNZ) announced this afternoon that it is retesting the samples.
Ten horses were imported from the United States on 23 March 2008. They tested negative prior to export in the US but positive when in quarantine in New Zealand. All the horses appear healthy and are not showing any symptoms of disease.
"There is a strong indication that cross-contamination in the laboratory was the reason for the positive results. The laboratory will be conducting further tests over the weekend to confirm that this is so. Further investigations will also be made to ascertain to how the tests in New Zealand became contaminated," said MAFBNZ's Import Standards Group Manager, Clive Gower-Collins.
As a precaution MAFBNZ has moved quickly to 'lock down' the Karaka facility. No horses will be allowed to leave or enter the site, and no visitors will be permitted entry.
"Current requirements are designed to identify unwanted viruses and diseases like influenza before horses are cleared. Under strict import standards horses are required to undergo 21 days quarantine before departure for New Zealand, including testing and vaccination, and a further 14 days in post-arrival quarantine in New Zealand, where they undergo further testing."
"The horses have been in quarantine since their arrival from the United States in a secure facility, so there is no risk to the New Zealand horse population."
MAFBNZ is confident testing over the weekend will confirm that the horses are free from disease. The New Zealand horse population is not at risk as any virus would be contained within the Karaka quarantine facility and allowed to run its course.
MAF BNZ is working closely with the New Zealand racing industry and Equine Health Association.
"The horses in question were picked up during standard quarantine procedures and we are pleased that MAFBNZ has moved quickly and taken every precaution in the protection of our industry," said New Zealand Racing Board Chief Executive, Graeme Hansen.