Investigators remain at the scene of the blaze which killed 34-year-old Wayne Godinet and his five children on Russell Island.
The family's 28-year-old mother, Samantha Stephenson, survived the inferno by escaping when the two-storey home was engulfed in flames about 6am on Sunday.
An investigation centre has been established at nearby Cleveland police station.
Detective Superintendent Andrew Massingham said some elements of the incident required closer scrutiny and investigators were "keeping an open mind" as to the cause.
"No determination has been made at this stage as to whether this fire is suspicious or not," he told reporters on Monday.
Det Supt Massingham said officers had previously been called to the house and Mr Godinet was known to police, although he would not give any further details of the interactions.
He said previous calls to the address were under review.
Police said a 21-year-old woman also escaped the house unharmed and they were hopeful to interview her and Ms Stephenson on Monday.
The two women were found by emergency crews outside the house suffering smoke inhalation.
Witnesses said Ms Stephenson was seen screaming for help, telling first responders her family was trapped inside the burning home.
The blaze spread to two other properties that were saved by firefighters.
Several people from the neighbouring properties were also treated for smoke inhalation and minor burns.
Three people were taken to hospitals on the mainland for treatment, including Ms Stephenson.
Authorities spent Sunday afternoon at the scene working to piece together the origin of the fire.
Fire investigators found the bodies of Mr Godinet and the five boys - aged 11, 10, twin four-year-olds and a three-year-old - inside the burnt-out home late on Sunday.
Police are hopeful of removing the bodies on Monday.
A post-mortem and scientific examination will be conducted to formally confirm their identities.
The small Russell Island community has been hard hit by the tragedy, with the victims known to local emergency personnel.
The eight-kilometre-long island lies between the Queensland mainland and North Stradbroke Island and has a population of about 3700.
Locals have paid tribute to the family both online and near the scene, as people gathered behind the police cordon on Monday to pay their respects.
The Bay Islands Memorial Gardens and Sel Outridge Park on the mainland are also open for people to pay tribute.
Redland City mayor Karen Williams said the community was in mourning.
"I talk about the islands and their isolation, but what brings with that is a really strong sense of community and everybody knows everybody," she told ABC Radio.
"This sort of grief will resonate right across not just this island, but all of our southern Moreton Bay islands and our city."
Local authorities are setting up a fundraising account through the local registered charitable trust, The Redland Foundation.
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