Firefighters have contained the perimeter of a four hectare grass and scrub fire near Lake Benmore in the Upper Waitaki area of Otago and are now mopping up hotspots.

Incident Controller Michael Harrison says the crews are mindful of the need to fully extinguish hot spots tonight as winds are forecast to increase in the area at the end of the week.

"Crews will also be back in the morning to continue this important work to prevent this fire flaring up again when the fire danger increases," he says.

The fire started in stubble around late this afternoon, burnt through paddocks and then moved up a hill into scrub.

Volunteer Fire Brigades from Twizel, Omarama, Otematata and Lake Tekapo all responded to the fire supported by three helicopters.

No homes or structures are reported to have been damaged or to be at risk.

Michael Harrison says the initial reports suggested that the fire had been sparked by farm machinery but there would be further discussions with the landowner to confirm the circumstances. He has asked all farmers and contractors in the area to be aware of the high fire danger because routine activities could cause a spark that would easily set the grass on fire.

"The fire danger will only increase as it gets windier as predicted," he says.

If machinery work couldn’t be deferred then it was best to carry out operations in the early morning, when the temperature is lower and the humidity was higher.

The whole of the Mackenzie Basin, including the Upper Waitaki area where the fire started, is in a prohibited fire season, which means there is a complete ban on outdoor fires.

This is the last update for this fire today unless there is a significant development.

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