A specially trained dog will spend the next few days pacing over the charred remains of a century-old derelict Sydney factory, amid fears human remains may be at the site.
The seven-storey former hat factory and a neighbouring building were destroyed in a catastrophic fire last month in Surry Hills.
The intense heat meant much of the brick and timber building collapsed and Fire and Rescue crews last week carried out major emergency demolition works to make the site safe.
The derelict building was known to regularly house rough sleepers, with 15 people counted in the building the night before the fire.
Despite efforts by police, two people who may have been inside have not been found.
Financial Crimes Squad Commander Gordon Arbinja says a cadaver dog will be combing over the site for at least three days.
"I hope we don't find any [deceased people], but it is possible," he told reporters on Monday.
The golden labrador, named Polar, will search for any evidence of human remains, before demolition crews return to the site to extract mounds of rubble.
Polar will then return and examine the site again, before more rubble is removed, and the site is again searched.
Any human remains found will be extracted and removed for forensic testing.
Three boys aged 13, and one aged 12, have been questioned by police about the massive blaze which lit up the city's night sky.
No charges had been laid, however anyone deemed responsible for the fire could be charged with malicious damage by fire, Det Supt Arbinja said.
Further charges could follow if human remains were found.
In NSW, police wanting to pursue charges against children aged between 10 and 14 need to present both evidence of the crime and evidence that the child knew what they were doing was wrong.
Police were also investigating whether an accelerant was been used.
About 130 residents were displaced in the immediate aftermath of the fire, and police, along with the Sydney City Council and local welfare agencies formed a recovery committee to communicate with those affected.
About 80 locals remain displaced, as the committee works on a plan to let residents move back into their homes.
One neighbouring apartment building is facing a month-long wait as engineers work on an electricity issue, while residents from a second apartment look likely to return later this week.
