More police will be deployed to investigate the cause of 12,000 bushfires across NSW this season, including more than 700 put down to human intervention.
But NSW Police say they'll continue to classify "deliberate" fires as any that are lit by people - even if there was no intention of taking property or life.
Assistant Commissioner Stuart Smith said 716 of the 1700 bushfires already reported to police this season had been classified as deliberate.
"It ranges from those that are listed as accidental right through to intentional," Mr Smith told reporters on Friday.
Another 156 were down to natural causes such as lightning, while more than 700 were yet to be classified.
The lead police investigative body for bushfires, expanded to 40 officers on Friday, will handle coronial investigations for 24 deaths and coordinate detectives probing the cause of 12,000 bushfires already recorded by the NSW Rural Fire Service this season.
"Intentional behaviour, serial behaviour, behaviour that needs to be profiled, takes a great deal of patience and scientific work to establish a list of individuals that we think need to have predictive or proactive work in the upcoming season," Mr Smith said.
Commissioner Mick Fuller said the destruction this season was "something like we've never seen before" and the investigative response had to meet that challenge.
People who don't perceive themselves as arsonists could be charged for starting fatal fires, Mr Fuller said.
"There are occasionally people who think they know better and on a catastrophic fire day start their own backburning," he told 2GB on Friday.
"We've just got to sharpen up because people are losing their lives, livelihoods and properties because of people who may not profile as arsonists but they're starting fires that are causing the loss of life."
Data released on Friday by NSW Police shows 267 people have faced legal action - ranging from cautions to criminal charges - over 328 bushfire-related incidents.
That includes 55 people behind allegedly deliberate fires, 126 people allegedly failing to comply with total fire bans and 41 people pursued over discarded cigarettes or matches.
Arson was the suspected cause of 1.3 per cent of fires recorded across NSW in the year to June 2019, NSW RFS Commissioner Shane Fitzsimmons told state parliament last year.
Four per cent of investigated fires were deemed "suspicious" - the same percentage attributed to campfires.
One in five blazes (21.6 per cent) were suspected to have been started by people burning off while 7.6 per cent were deemed caused by lightning.
Australian Associated Press