Tests have determined that the bacterial disease found on gold kiwifruit vines in the Bay of Plenty is indeed PSA.
However, they have not yet established what strain it is.
The Government earlier said it would be Wednesday before the disease could be confirmed.
The Ministry of Agriculture and Fisheries had said it was 95 per cent sure it was the pest, and precautions had been taken to minimise any possible spread.
The affected orchard is surrounded by other kiwifruit-growing properties.
The disease affects only kiwifruit vines, and is spread by wind, bees and poor agricultural hygiene.
Kiwfruit marketer Zespri says that if the disease is confirmed, it could have serious implications for growers. Last year, global kiwifruit sales through Zespri were worth $1.5 billion.