A fire crew was still on duty at Flat Top Hill yesterday after a flare-up on the site on Tuesday night, but light rain during the day helped douse hot spots.
Department of Conservation deputy principal rural fire officer Trevor Mitchell said he hoped the fire was extinguished now but the area would be patrolled by Doc fire staff for the next few days.
The fire burned 20ha of the Flat Top Hill conservation area on Monday and its cause is still a mystery.
The cold weather and light rain yesterday morning helped cool the area down, Mr Mitchell said.
Investigations into the cause of the fire were continuing, although no new information had come to light.
