Emergency services were called to a home on Fairfield Avenue just after 4.30 on Saturday morning where they found a 6-month-old boy had gone into cardiac arrest.
He was rushed to the John Hunter Hospital in a critical condition but despite the best efforts of medical staff, he died late on Sunday.
A post mortem examination determined the little boy died as a result of a traumatic head injury.
Detectives arrested a 28-year-old man at Budgewoi yesterday.
He's been refused bail to face Wyong Local Court today charged with murder and reckless grievous bodily harm.
