Police are investigating a fire they say was deliberately lit at Warrungup Spring Reserve in Dawesville on January 19.
A spokesperson for the Department of Fire and Emergency Services (DFES) said they received a call around 6.25pm from a member of the public about the fire, and sent down career firefighters from Mandurah Fire and Rescue and volunteers from Falcon Volunteer Fire and Rescue.
"Someone had seen a fire behind a house on Durham Crescent," the spokesperson said.
"When crews arrived the fire was about 50sqm in size."
The fire had reached and burned a large area of bushland adjacent to a firebreak path, but had luckily not reached any houses on the street when crews arrived.
"In about an hour, by 7.25pm the fire was out and the crew made the area safe to return to.
"The fire was deemed by police to be suspicious."
Investigators said they were looking to speak to anyone who saw suspicious people or activity in the area at the time, in particular along the Jinatong Trail and surrounding streets.
The spokesperson said they could not comment in regards to the suspicious nature of this particular fire, but there were several reasons fires could be deemed suspicious.
"If they went down there and couldn't see anything that would indicate how it would start naturally - for example, if it was a lightning strike they may see the point of impact.
"Or if it was an accident, like a discarded cigarette, they may find the butt. If there's no apparent reason the fire occurred naturally that's when it may be deemed suspicious."
Mandurah police took to Facebook to let the public know that there is a reward of up to $25,000 offered for any information which leads to the conviction of an arsonist in Western Australia.
Members of the public with information relating to this fire are urged to contact Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au.
Anyone with mobile phone, CCTV or dash-cam vision of the area can upload the vision direct to investigators at https://wapf.au.evidence.com/.../public/190122204016273.
Police have been contact for further information.
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