Detectives have launched a homicide investigation after a suspicious house fire in north Queensland claimed a woman's life.
Acting Chief Superintendent Chris Lawson said detectives believed the fire was deliberately lit.
The 47-year-old woman suffered severe burns and died in hospital after the blaze in the rural town of Ayr on Tuesday morning.
The woman's partner, a 65-year-old man, remains in a serious condition in the Royal Brisbane Hospital and police have been unable to speak with him.
Police attended the home for a welfare check just hours before the blaze broke out and spoke to the couple.
Acting Chief Superintendent Lawson said that interaction was now the subject of an internal police review.
"We don't want to rule anything out at this stage and we don't want to speculate — until we actually speak with this male [it] is difficult for us to establish exactly what the reasoning behind the whole incident was," he said.
"The man and woman were in a domestic relationship and there was a current domestic violence protection order protecting the 47-year-old female.
"We're working closely with the staff at the hospital to ensure that as soon as [the man] is able to, he will be speaking with the police."
Acting Chief Superintendent Lawson said the domestic violence order had been in place since 2018 and did not prohibit the couple from living together.
He said they had lived at the property in Ayr for about a year before the fire and were known to police.
He said officers had been called to the property before the fire.
"We received a call for a request for service and we attended the scene," he said.
"At that stage, police received assistance from the Queensland Ambulance Service to conduct investigations into the matter that was before them, and as a result of that they left both parties at the address.
"It's not a great result and that's why we have the Ethical Standards Command and the CCC [Crime and Corruption Commission] overviewing the investigation into that initial interaction with the couple."
Police have been doorknocking residents in Ayr and have urged anyone with relevant CCTV or dashcam footage to contact them.
"The Queensland Police Service has launched a homicide investigation, codenamed Operation Uniform Turmeric, in relation to this investigation," Acting Chief Superintendent Lawson said.
"Our investigators will be looking to glean as much information from the community around the couple and what their interactions were with them."