ONLY a "transparent and independent" investigation into the Toodyay bushfire will establish its cause, says a lawyer acting for victims of Western Australia's worst bushfire in almost 50 years.
Kevin Banks-Smith, who represents more than 70 victims of the Toodyay fire, said residents were unhappy with a report by WA power industry watchdog EnergySafety into the cause of the blaze.
But WA Premier Colin Barnett has backed the investigation, saying the report was conducted without any influence from the state government or Western Power.
"The EnergySafety report is a totally independent report, independent of Western Power, independent of the government, and done to a high-technical standard," Mr Barnett said.
"If significant new information or evidence came forward, of course EnergySafety would look at it. I'm not aware of any new significant evidence.
"If people wish to try and pursue this through the courts, that's their choice."
The Toodyay fire wiped out 38 homes, three holiday cottages and 20 sheds when it ripped through 3000ha of bushland near the wheatbelt town on December 29 last year.
The destruction of stock, fencing and farm machinery contributed to an estimated property damage bill of more than $100 million - the worst property damage wrought by any bushfire in WA since 1961.
Almost immediately after the fire, suspicion centred on a power line in a paddock west of the township which was reported to have fallen down and possibly sparked the fire.
The state-owned utility Western Power initially said its investigations indicated the fire had started in this vicinity and acknowledged the possibility that one of its powerlines was responsible.
But EnergySafety released a report last Thursday ruling out a fallen power pole or pole-top fire as the cause of the blaze and clearing Western Power of any blame.
This was despite a report to EnergySafety by Western Power which said arc marks found on two wires near the source of the fire indicated they had clashed, causing a short circuit.
EnergySafety said its investigation could not determine the cause of the arc marks and whether or when a clash had occurred, or whether this had caused the fire.
Mr Banks-Smith said that after a 2007 Toodyay fire, which caused far less damage, a firm of electrical consulting engineers found it was caused by a clash in lines which dropped molten metal to the ground.
He said no independent electrical engineer had been commissioned to investigate the December 29 fires.
Mr Banks-Smith said Western Power acknowledged that its own computer records showed the fire started "directly below fresh arc marks on its power line at 12.53pm".
"The first triple-0 call to report the fire was made at 12.57pm," he said.
"There is a logic trap in any thesis that wants to say the fire came before the incident on the line."
Mr Banks-Smith said the EnergySafety report had been published before the release of a report by a metallurgist who had been commissioned to investigate possible power line damage.
"They say the report by the metallurgist isn't yet available," he said.
"We find it very difficult to understand why Western Power and EnergySafety have made their findings in advance that report."
Mr Banks-Smith said only a "full, open and transparent independent investigation" into the cause of the fire will satisfy Toodyay residents.
"They're just asking for a fair go," he said.
"We could liken this inquiry to the health authority asking a tobacco company if cigarettes are harmful."