A new strain of the deadly rabbit calicivirus is being prepared and scientists are calling on farmers this time to co-operate over its release.
When calicivirus first came on the scene in the 1990s local farmers took it on themselves to illegally import it from Australia but in some places the rabbit population is back to really damaging levels.
Landcare Research is now testing a new Korean strain of calicivirus and news that 'K5' could be coming is being welcomed by those dealing with the pests.
And farmers are vowing not to repeat the vigilante actions which led to the major biosecurity in the 1990s.
"It would be a very big surprise to me, I think the financial climate and climatic conditions are quite different to what they were," Tarras farmer Bruce Jolly says.
The new strain will specifically target rabbits that have developed an immunity to the original virus and Dr Janine Duckworth from Landcare Research says if materials are introduced illegally they could bring in other viruses not wanted in New Zealand.
Before it can be released in New Zealand the new virus will need approval from the Ministry for Primary Industries and the Environmental Protection Agency.
K5, which scientists say only affects rabbits, could be ready for release by next autumn.