Police were scouring Griffith Park at Stockton on Sunday after a woman was assaulted the previous night.
Officers and paramedics were called to the waterfront park off Hunter Street, near the harbour ferry terminal, about 6pm.
In a brief statement, NSW Police said they had declared a crime scene and were making inquiries.
Residents reported a heavy police presence in the suburb into Saturday evening as officers canvassed the area, and officers were on the scene again on Sunday into the afternoon.
Paramedics assessed an adult woman at the scene who was lager taken to hospital for further treatment.
Police have declined to provide further details on the woman's condition, and said on Sunday afternoon that their investigations were ongoing.
Newcastle City Police District officers have urged anyone with information about the incident to come forward as their investigation continues.
Witnesses or those who may know more have been urged to contact Newcastle police station or Crime Stoppers, on 1800 333 000, where details can be provided anonymously.
