Investigators believe the fire was deliberately lit, with police yet to formally identify the bodies found inside the Browns Plains home.
This article contains references to domestic violence.
A Queensland grandmother who perished in a suspicious house fire had recently taken out a protection order.
Tributes are flowing for 49-year-old Doreen Langham on social media pages that campaign against domestic violence.
Media reports have also named Ms Langham as a victim of Monday's blaze, south of Brisbane, along with a 49-year-old man identified as her ex-partner Gary Hely.
Police are yet to formally identify the bodies found inside the blackened shell of a Browns Plains home and are awaiting the results of an autopsy.
Investigators believe the fire was deliberately lit.
Premier Annastacia Palaszczuk spoke of the tragedy on Tuesday, saying: "It's unbelievable this is happening in this day and age."
On Monday, Acting Detective Inspector Daniel Cunningham said it could take investigators up to a week to prepare a report about the cause of the blaze.
He confirmed a temporary protection order was issued by Beenleigh Magistrates Court on February 9, without confirming any identities.
Speaking on Tuesday, Chief Superintendent Brian Swan said the investigation will be overviewed by the state coroner as a death in relation to a police investigation.
Mr Swan stated the reason being, is that enquiries indicate that on the night before the fire there was a phone call made to police, and that police did attend the unit.
"The call was made in the evening of Sunday ... some time after 9pm, and police attended, it would seem after midnight."
Police do not know the full extent of enquires at the scene before the fire, but that will be examined in detail in the coronial investigation, Mr Swan said.
Police are calling for anyone with information about the couple or the blaze to come forward.
If you or someone you know is impacted by sexual assault, family or domestic violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au. In an emergency, call 000.
Readers seeking support can contact Lifeline crisis support on 13 11 14, Suicide Call Back Service on 1300 659 467 and Kids Helpline on 1800 55 1800 (for young people aged 5 to 25). More information is available at Beyond Blue.org.au and lifeline.org.au.