The Minister for Primary Industries has admitted that the bill for the fruit fly emergency in Auckland is likely to be in the millions of dollars, even if no more flies are found.
David Carter says it is looking increasingly likely that they will not find any more of the pests.
One male Queensland fruit fly was found in the Auckland suburb of Avondale on Tuesday and the Ministry of Primary Industries is investigating whether it is part of a colony.
Horticulture New Zealand says the Queensland fruit fly is regarded as the biggest threat to the $4 billion fruit and vegetable export industry because of the damage it can do to a wide range of produce and the potential disruption to trade.
This type of fruit fly is considered Australia's most serious horticulture pest species.
Up to 50 ministry staff spent Sunday morning at the popular Avondale Market which is held just outside a 1.5km controlled area that has been established around the Wolverton Street property where the insect was found.
Several feijoas and a capsicum which may have come from inside the zone have been seized and destroyed.
Ministry staff have have already placed 71 traps within 200 metres of where the pest was caught. The lures can attract fruit flies from 400 metres away and are being inspected daily.
Mr Carter says it's looking increasingly likely that there will not be a fruit fly outbreak, but staff will continue examining fruit and checking for larvae until they can rule out a biosecurity threat.
Mr Carter visited the Avondale Market on Sunday to talk about the threat with stall holders and local people.
He told stallholders that inspectors haven't found any more fruit flies, a good sign, he says, that the threat will not eventuate.
Mr Carter says staff will continue with their cautious approach over the coming fortnight, with fruit exclusion zones, and traps remaining in place.
Extra staff will arrive in Auckland on Monday to assist.
He admitted that the bill, if no more flies are found, is still likely to be in the millions of dollars.
Meanwhile, some fruit sellers at Avondale Market say there were noticeably fewer people on Sunday, which they believe has hurt their business.