POLICE said a car's hot exhaust was the cause of a fire that ripped through grassland in Wedderburn on Monday.
Maryborough Sergeant Yan Stroek said the car belonged to the owner of the property.
A State Control Centre spokesperson said the fire burnt 40 hectares of land.
"The fire was on grassland, on private property near the Calder Highway at Skinners Flat," the spokesperson said.
Kerang CFA operations officer John Cutting said no properties were threatened.
"Ten units were on the scene with air support attending from Bendigo," he said.