COSTLY restoration work is needed to two historical Kurnell monuments at Kurnell which were defaced on the Australia Day long weekend.
Black paint was splattered on the obelisks commemorating Captain (then lieutenant) James Cook and botanist Daniel Solander, who sailed into Botany Bay aboard the Endeavour in 1770.
No official statement about the vandalism was made to the media at the time it took place.
After inquiries by the Leader, a spokeswoman for the NSW Office of Environment and Heritage said the monuments were defaced over the Australia Day long weekend.
"Vandalism to both monuments was reported by our local staff at the time," she said.
"Given the heritage importance of the structures, which are made of sandstone, we will be using a specialist contractor to repair the damage in the next few weeks."
Before Australia Day last year, black paint was used to scrawl graffiti, condemning white settlement, on walls and structures between Brighton-Le-Sands and Sans Souci.