Arson Squad detectives are investigating a fire at a vehicle scrap business in Forestdale that occurred last week.
The blaze was sparked by a batter powered angle grinder just after 3.30am on Wednesday February 24.
Around 3am the offender entered the yard through a damage fenced to look through wrecked vehicles.
The offender used an angle grinder on a vehicle, which ignited a fire that damaged 50 scrap vehicles.
It is likely the offender received burns to his arms according to police.
The damage of the property is estimated between $5,000 and $20,000.
Arson Squad detectives ask anyone in the area around the time of the fire with CCTV, mobile phone or dash-cam vision, to come forward.
Anyone with information regarding this fire, is urged to call Crime Stoppers on 1800 333 000 or report online at www.crimestopperswa.com.au.