A body and a gun have been recovered from a dam on the rural New South Wales property where a woman and her three children were found dead.
Wagga Wagga police said a gun was found with the body that is believed to be that of 44-year-old Geoff Hunt, whose wife and children's bodies were discovered yesterday.
Police said divers found the fifth body in a dam on the property.
Kim Hunt, her 10-year-old son Fletcher and daughters Mia and Phoebe, aged eight and six, were found dead at a farmhouse near Lockhart, west of Wagga Wagga, earlier in the day.
The Australian flew at half-mast at a the school where the children were students.
The remaining 71 pupils and teachers at the school were mourning the death of the siblings, St Joseph's Primary principal Debbie Sheather said.
She said the children would be deeply missed at the school.
"They were always full of laughs and they were really talented in what they did and they worked really hard, they were just beautiful kids and of course all of their friends at school miss them."
The ABC reported that Mr Hunt was a local farmer, while his wife was a well-known nurse and the local community was said to be devastated by the tragedy.