Emergency services rushed to a home in the suburb of Miller in Sydney's south west after they received a call of concern for the welfare of a child just after midday on Tuesday.
"Upon arrival officers located a two-year-old female deceased," a NSW police spokesperson told BuzzFeed News.
"A post mortem will be conducted to determine the official cause of death."
A crime scene has been established and no one has been arrested or charged.
Gina Rushton is a breaking news reporter for BuzzFeed News and is based in Sydney.
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