Fire and Emergency New Zealand (Fenz) was alerted to the fire in Mackenzie Rd, near Livingstone, about 3.15am on Sunday, and a small number of residents self-evacuated.
It was fanned by high winds and was in a rugged area, which made it hard to contain, a Fenz spokesman said.
Several fire crews and helicopters fought the blaze on Sunday and Monday, including a fire command unit from Dunedin.
"Our understanding is a tree from well outside the notice zone of the powerlines has come down across the powerlines, and that’s brought them down and potentially led to fire," Network Waitaki chief executive Geoff Douch said.
"That’s our understanding at this stage. It’s being investigated by Fire and Emergency, so we don’t have that as a definitive cause, but we did have lines down."
About 48 homes in the Livingstone and Tokarahi area were without power on Sunday night. Power was restored to most homes on Monday, but some had to wait until Tuesday, due to safety concerns and forecast high winds, Mr Douch said.
"We wanted to keep it off until [we knew] what damage had been done and once the fire service had given us the all-clear," he said.
Planned power outages were expected for more replacement work to be completed.
"It’s safe, but we want to get in there and fix up a couple of things that we’ve now seen."
A shed was destroyed in Smith Rd, but a house and garage on the same property were saved. No other property damage was reported.
Yesterday, fire crews were continuing to monitor the scene.
A Fenz spokesman said the blaze had been contained and there were no visible signs of fire, but crews would continue "patrolling the fire ground over the next few days and will re-evaluate next week''.
"If anyone sees smoke please ring 111 immediately,'' the spokesman said.
