A 60-hectare fire is raging in a conservation area near Invercargill on Monday night and it could take firefighters days to put it out.
Fire crews with the assistance of two helicopters are battling the blaze in and around Awarua Bay, about 20km south of Invercargill, says Fire Service southern communications centre shift manager Karl Patterson.
The fire was reported about 6.15pm and Mr Patterson says it could take firefighters up to two days to put out.
"It terms of fires in New Zealand, this is a big one," Mr Patterson told NZ Newswire.
He says a strong wind in the area is fuelling the fire which is spreading.
No-one has been hurt in the blaze and there are no buildings nearby.
The Department of Conservation website describes the Awarua Wetlands as one of the largest remaining wetlands and is recognised for its biological diversity and cultural values.
The wetlands include coastal lagoons, freshwater swamps, extensive peatlands and estuaries.
Awarua Bay is a significant site because it is host to a number of bird species.