SYDNEY - Fire authorities' investigation has suggested that a massive bushfire that destroyed more than 50 homes in the Perth Hills area of Western Australia was probably sparked by a power pole on private land, local media reported on Tuesday.

Western Australia's Department of Fire and Emergency Services (DFES) Superintendent Gary Baxter told ABC radio on Tuesday that 52 properties have been destroyed by the fire over the last two days.

He said DFES investigators believe the fire was started by a power pole.

"All our indicators and our investigation team have led us to believe that," Baxter said.

The fire was contained on Monday but firefighters are still battling to bring it fully under control.

Firefighters are concerned that strong winds could cause flare-ups.

The fire, which started in Parkerville before spreading to Stoneville on Sunday, has burnt through almost 400 hectares in the area.

Hundreds of residents who were evacuated have not been allowed to return home as authorities believe it is too hot and dangerous to do so.

Four people who were feared missing in the fire were accounted for on Monday, local media reports said.