Oceana Gold, which operates the Macraes mine in Otago, has raised its reserves estimate for a third time and expects to increase it again.
The Melbourne-based company says it has found another 259,000 ounces of gold at the site, which will increase the life of the mine to 2016.
This follows an increase of nearly 650,000 ounces of gold in November and December.
The company says rising gold prices and cheaper extraction methods are making it more economical to extract gold from the site.
