Three bodies, including those of two children, have been found at a Hillier house, near Gawler, in Adelaide's north, ABC reports.
Police were called to the house on Jack Cooper Drive at 1:30pm.
Police in a statement said officers found a man outside the home and discovered the bodies of two children and an adult woman inside the house.
The man has been taken to the Lyell McEwin Hospital and remains under police guard.
At least five police vehicles are at the home which is situated in a rural setting and surrounded by trees.
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