The New South Wales Police Child Abuse Squad is investigating the suspected assault of a nine-week-old boy in the Lake Macquarie area.

Police were notified last month when a baby boy was taken to Newcastle’s John Hunter Hospital suffering serious injuries, including multiple fractures and bruising.

Medical experts have told police the fractures are consistent with the baby being shaken, and the bruising consistent with the child being bitten by an adult.

The exact cause of the injuries is still unknown.

The boy is now 16-weeks-old and in the care of the Department of Family and Community Services.

Detectives have formed Strike Force Glendevie to investigate the incident and are appealing for assistance from anyone with information to come forward.