A baby girl has died after been found dead inside a home at Villawood in Sydney's south-west.


Police visited the home on Goondah Street at 8:30am on Monday where they found a five-month-old girl unconscious.


An ambulance was called and she was taken to Liverpool Hospital but she could not be revived.


Detectives are now investigating how the girl died and the single-storey brick home is now a crime scene.


A NSW Police spokeswoman said the baby’s death was being treated as suspicious at this stage, as would be the case with any sudden, unexplained death.


The baby's parents are believed to have called triple-0.