NSW toddler dies in hospital

A 19-month-old boy has died in hospital after paramedics found him unconscious and not breathing in a home in the NSW Hunter region.

It's unclear whether the toddler's death is suspicious and police have set up a crime scene at the Cessnock home, where he was found in the early hours of Wednesday.

When paramedics arrived, CPR was being administered to the boy as he had gone into cardiac arrest.

An ambulance spokeswoman wouldn't say whether it was the boy's parents trying to resuscitate him.

Following further attempts to restart his heart, he was taken to Cessnock Hospital, where he died.

A police spokeswoman was unable to tell AAP what caused the boy to lose consciousness.