Recent testing of a wild Bluff oyster fishery has found no sign of a lethal parasite that could threaten the industry.
When oysters near Stewart Island were found in May to be carrying bonamia ostreae, farmed oysters were culled around Stewart Island and in Marlborough to stop further infection.
One farmer went out of business as a result.
The director of readiness and response at the Ministry for Primary Industries, Geoff Gwyn, said the all-clear was great news for the local industry.
Among the areas tested were wild flat oyster fisheries throughout New Zealand, including places that hadn't been looked at before.
Oyster farms are still being removed from Malborough to prevent the parasite spreading.