Compare with this male which is closely related if not the same species. In many fly species the males have a narrower gap between the top of the eyes.
Classification
from Australian Faunal Directory
Order Diptera - Flies, 8955 named species in Australia at Nov. 2021
Division Cyclorrhapha - Flies having Short Antennae with a Bristle or Arista
Family Calliphoridae - Blowflies and Bluebottles, 120 named species in Australia
Genus Calliphora
Species ?