Cairns police say that there were five fathers to the eight children who were found were found following what was believed to be a multiple stabbing yesterday.
Mersane Warria, the 37-year-old mother of seven of the eight children has been arrested for murder, the ABC reported.
Four girls aged 14, 12, 11 and two, and four boys aged nine, eight, six and five were found in Murray Street, Manoora, where the 37-year-old woman was also located.
Acting Assistant Commissioner Paul Taylor said there were five fathers to the children, and police had been in contact with all five men about the killings.
He said charges would be laid when it was "appropriate and everything's completed".
"Overnight we had the forensic people in the house. The deceased have been removed from the house," Detective Inspector Bruno Asnicar said.
"Today we will have our coroner and pathologist conducting their investigations with the assistance of the family."
Detective Inspector Asnicar said police were not looking for anyone else in relation to the deaths and were comfortable the community was safe.
He dismissed speculation the Manoora house had been the subject of calls from the Department of Social Services.
"It's not a problem house, as has been speculated," he said.
"This is an ordinary neighbourhood, a lot of good people, a lot of kids in the area. This is something that has caught everybody by surprise."
Police said a number of possible weapons including knives were located in the house.
They said the investigation would take time and officers from Brisbane and Townsville had arrived yesterday afternoon to assist with the complex investigation.