Their bodies were found by police, who went to the Glenelg North home about 11pm on Thursday night.

Due to the sensitive nature of the deaths, police said they would not comment on how the tragedy happened.

Concern was raised by the woman's estranged partner during the afternoon on Thursday, when he couldn't make contact her by phone, police said.

That prompted police to visit the Shannon Avenue property once during the day, and again at about 11pm.

"The initial investigation was prompted from a family member and that's prompted the ongoing investigation from that time on, which culminated in the location of the deceased persons," Detective Chief Inspector Wayne Overmeyer said at the scene on Friday morning.

"An investigation is continuing and it's in its infancy, however, it is believed there is no other person involved in these tragic circumstances."

The woman was in her 40s.

Inspector Overmeyer said the woman's estranged partner was "not doing very well at all".

"These circumstances are tragic for anyone who is exposed to them and it's appropriate that we respect everybody, particularly the deceased, and we make sure we do a thorough job and prepare a proper report for the coroner," he said.

Police take evidence from #Glenelg Nth house, where bodies of woman & child found at 11pm, not searching for anyone re deaths #FIVEaaNews pic.twitter.com/gVemvN1xHb??? Matthew Pantelis (@MatthewPantelis) May 25, 2017

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