Baby boy found dead at a home in Chester Hill

Police are investigating whether a toddler died after being left in a hot car at a home in Sydney's west.

The 22-month-old boy died after he was found unconscious inside a home in Chester Hill on Sunday afternoon.

Emergency services were called to a home on O'Hagon Street about 3.30pm after reports that a baby boy was unresponsive.

NSW Ambulance paramedics were unable to revive the boy.

Police were told the child was found inside a car at the front of the residence by family members when he could not be found inside the home.

The boy, said to be a twin and the youngest of six children, was reportedly left in the care of someone else while his mother was out.

After police had roped off the street, a woman was seen running towards the home, before later breaking down while talking to police.

Police have established a crime scene and are investigating the cause of death.

With AAP