The gravestones of a prominent Stockton identity and other former locals have been knocked over in an incident described as "sad" and "disappointing".
Lesley Thompson of Dungog is a regular visitor to the area, and assists people with family research by photographing headstones for website FindAGrave.
She was at Stockton on May 31 when she noticed some headstones were not upright.
One belongs to Hugh Boyce, who was the first person to run a ferry between Stockton and Newcastle.
Mr Boyce commenced the service in 1853 using a rowing boat and later operated steam ferries across the stretch, according to Stockton Historical Society.
Ms Thompson said she was shocked to see his gravestone and others had been knocked down, describing it as "sad."
"Important people in our history should not be treated this way in death or life," she said.
Ms Thompson alerted Stockton Historical Society to the matter.
Historical society research officer Michelle Watson said no one from the society had been able to go and have a look, but that it was "always a concern when any historical monument is damaged".
"Anytime something happens in a cemetery it is quite confronting for community," she said.
"Hopefully if it is the result of vandalism they can be repaired and mitigation processes put in place to stop it happening again."
City of Newcastle confirmed it was aware of reports of headstones in Stockton Cemetery being vandalised.
"It is disappointing to see vandalism yet again to our community spaces and we condemn this activity," a spokesperson for City of Newcastle said.
"Anyone's final resting place deserves to be treated with sensitivity, dignity and respect.
"The community can report any instances of vandalism after hours by phoning police on 1800 333 000 or City of Newcastle on 4974 2000."
Ms Watson said Newcastle Family History Society had recorded local gravestones, so they have the data to help replace headstones if they are damaged or go missing.
"Luckily it doesn't look like there was any other damage in this case," she said. "Hopefully it will be not too difficult to get the headstones back in place."