''Farmers are advised not to intervene and let the virus spread naturally. They should also undertake traditional control on surviving rabbits as these are likely to be immune to RHDV1.
''Autumn-winter is generally the best time to undertake control, but certainly outside the rabbit breeding season,'' Mr Sullivan said.
Otago Regional Council environmental monitoring and operations director Scott MacLean said about 80% of the sites where the virus was released in that region had shown a decrease in rabbit numbers.
Reductions were in the range of 0% to 80%, the average being 29.9% - in line with expectations.
''We have 10 rabbit samples from the field which have tested positive for RHDV1 K5. This indicates that K5 is active in the wild rabbit population,'' Mr MacLean said.
''If anyone finds a dead rabbit which is not exhibiting signs of an obvious cause of death, it would be hugely appreciated if they contact us to let us know.''