A mother and her three children found dead in their home in Tullamarine, Victoria, have been identified.
The bodies of Katie Perinovic and her children Matthew, three, Anna, five, and Claire, seven, were discovered after the childrens father, Katies husband Tomislav, 48, called triple-zero at around 12.30pm on Tuesday.
When paramedics arrived he was standing on the front lawn of his Burgess Street home.
Police say he is assisting them with their inquiries but that the investigation is still in its early stages.
The family reportedly lived at the home together and there was no history of family violence.
The homicide squad is investigating all avenues, including the possibility the deaths could be the result of a murder-suicide.
Victoria Police Acting Deputy Commissioner, Bob Hill, said no assumptions should be made about what had unfolded.
Theres been a tragic event in metropolitan Melbourne today, he said.
The loss of four lives, a mother and three children, is a tragic event.
When it involves children, it is more heart-wrenching.
Hill said police were not looking for anyone else in relation to the tragedy.
I must be very clear here and advise that at this point in time the investigation is at its very early stages, he said. We know it involves a husband, a wife, and three children.
The circumstance of this event are yet to be determined. We cannot afford to make any assumptions as to what occurred.
There are many scenarios that we need to actually explore. I just want to make it clear& we should not assume culpability on the basis that we have a male assisting us with our inquiries.
Hill added drawing conclusions about the husband would be grossly unfair.
He did not expect any charges to be laid on Thursday.
We well and truly have a long way to go before we can actually understand ... what has occurred, he added.
Detectives declined to comment on the nature of the injuries sustained by the deceased.
Forensic officers continued to comb the scene on Thursday night, with police speaking to neighbours and those known to the family.
Katie Perinovic worked at Glenroy Physiotherapy for several years but left the clinic unexpectedly three months ago, the Herald Sun reports.
She graduated from the University of Melbourne in 1999, according to its website, and specialised in physiotherapy and Feldenkrais.
Neighbours told 7NEWS they were shocked by the tragedy.
One neighbour described Katie Perinovic as polite and friendly, someone who would always say hello.
Devastated, its so close to home, these people have spent time in my home, another neighbour said.
My kids loved their kids. How am I going to tell my kids?
Acting Assistant Commissioner Mark Galliot said first responders at the scene would be affected by the tragedy for years to come.
The loss of any life is tragic. However, the loss of young lives in circumstances such as this is are difficult to comprehend, he told reporters.
This will have long-lasting effects on the police that have attended, on extended family, the community, the neighbourhood, the emergency services, and everybody else involved.