The Karnak blaze, 15 kilometres south-east of Goroke, started on private property about 3pm on Tuesday and burnt through Kalingur State Forest.

The fire burnt about 900 hectares.

Department of Sustainability and Environment, Parks Victoria and Country Fire Authority crews controlled the fire by 8pm on Wednesday.

Fire-fighters will continue to black out the fire for about a week.

A decommissioned windmill started the fire.

Fire investigators believe wire restraining the windmill became loose, causing the windmill to start turning.

Incident controller Russell Manning said a helicopter fitted with a Forward Looking Infrared - FLIR - camera, usually for military aircraft, helped crews at Karnak yesterday.

"We have used these units in the past, but this is the latest one," Mr Manning said.

"It was at the fire near Ballarat and has been sent up here.

"The unit takes images of the fire and detects hotspots.

"We then get that information on a map and use it to direct ground crews into those hotspots.

"This new unit is a great innovation that is being used for the first time in the Wimmera today."

Mr Manning said the severe fire danger rating forecast for the Wimmera today would not affect the status of the Karnak fire.

"We are actively working on the fire to continue to extinguish everything and ensure it is completely safe," he said.

"We are focusing our efforts on the southern edge, which will come under pressure with the northerly winds forecast.

"Again, about 25 to 30 fire-fighters will be working at Karnak on Friday.

"We also have lightning forecast overnight in the Wimmera and we are planning for potential fires from this."

Mr Manning advised people to check for potential fire ignition sources on their properties.

"The decommissioned windmill at Karnak was an ignition source we would not predict," Mr Manning

said.

"Usually fires start from slashing or campfires.

"But other ignition sources such as electric fences, cars or firewood cutting have all started fires," he said.