Wollongong police have sent what is believed to be a human bone away for forensic examination after it was discovered in the Royal National Park on Monday afternoon.
A NSW police spokeswoman said a bushwalker had stumbled across the object near a creek, adjacent to Lady Wakehurst Drive, and then reported it.
Police then established a crime scene in the area, retrieved the suspected bone and sent it away for examination.
The crime scene was established about 2.15pm on Monday and was in place until at least late yesterday.
Results from the lab are expected to be known within the coming days.
The police spokeswoman would not comment on what the bone looked like, or its age.