Written by Heather Chalmers and Esther Taunton
Investigations into the entry of cow disease Mycoplasma bovis into New Zealand continue, but Ministry of Primary Industries officials concede they are unlikely to find the culprit.
Biosecurity NZ head Roger Smith told a primary production select committee that it remains committed to finding the source of the outbreak. "The chance of finding someone who imported M. bovis is very slim.
"I don't expect to be charging anyone for importing the bacteria."
Investigations may uncover people who had committed offences under the Biosecurity Act, but directly linking them to the M. bovis outbreak was unlikely. Some practices may need tightening up, or be in breach of regulations.
MPI director-general Martyn Dunne said he and Agriculture Minister Damien O'Connor publicly appealed to people in Ashburton "if you have more information give it to us".
"This investigation is never over. We have solid grounds in a particular area.
"There are several other big incursions where we thought we had no grounds for further investigation, but have since been reopened," said Dunne.
An MPI spokesperson later said that regarding the reference to Ashburton, "we make this appeal throughout the country wherever there are affected properties" .
MPI officials visited two properties in March, as part of their investigation into the outbreak.
In a phased eradication costing $886 million, the Government will cull about 126,000 cattle on top of the 26,000 already being destroyed in an attempt to rid the country of the disease, which can cause mastitis and lameness in stressed cows. The disease is harmless to humans.
Visiting the national Fieldays in Hamilton, O'Connor said it was always going to be difficult to pin down legal liability for the introduction of the disease. "Investigations are still underway. I don't get regular briefings, I trust that they will update me but I haven't given up on finding out how it arrived.
"All avenues are being looked at and any law that has been broken - that might be in offshore preparations, the pathway into New Zealand or handling in New Zealand - could lead to charges."
O'Connor told the select committee that practices such as parallel-imported veterinary medicines and dispensing of vet products remotely, without physically examining animals "aren't smart and something we may have to review and if necessary shut down."
"If these are more than a low risk, we have to consider whether this pathway should stay open.
"These are clearly marginally ethical practices for vets in my view."
MPI continues to examine potential entry pathways including imported frozen semen, live cattle, embryos, veterinary medicines and biological products and imported used farm equipment.
Smith said tracing by MPI showed M. bovis arrived in a single incursion around December 2015 or January 2016. "This is based on the best science we have and the best genome sequencing. Using carbon dating we can trace it back, which indicates this date. This also aligns with our tracing of each farm."
He said other people held different views and believed it arrived earlier.