Detective Inspector Tom Armitt has confirmed the circumstances surrounding the death of boy are inconsistent with drowning.
"The circumstances surrounding how and why that child was located in the pool remain unknown,” Inspector Armitt said.
"However, it's believed that the child was deceased prior to being placed [in] the pool".
"Anyone who was travelling in the area at the time, who might have driven past the past the address, might have noticed something that might have been untoward or suspicious," the Inspector said
Mackay Detectives from the Child Protection Investigation Unit’s (CPIU) State Child Trauma Unit are conducting the ongoing investigation.
Police have now commenced a homicide investigation code-named Operation Tango Anise.
Authorities are appealing for anyone who may have further information to contact Policelink at www.police.qld.gov.au/reporting or call 131 444.
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