Most bones were unidentifiable but she thought one had human resemblances, and a physio agreed.
"There were fragments of bones whereas, if it was a full human skull or something like that, that would have been more disconcerting."
Kororāreka Marae chair Deb Rewiri said old bones that appeared human should not be disturbed.
"It's a bit disheartening to think that somebody has just picked up the bones, we don't know how they've been uncovered."
She said protocols needed to be observed, involving karakia and kaumātua, before possible human remains were moved.
"It's about the tikanga. I was surprised that somebody had just randomly dropped them off, but I thought it was somebody probably unaware of what to do."
Rewiri hoped the person who found the bones would come forward to help identify where they came from and whether there could be more nearby.
Heritage New Zealand is wary that kōiwi tangata and animal bones will continue to emerge from ancient and early settlements in Te Tai Tokerau.
Climate change is also expected to worsen coastal erosion.
Heritage New Zealand senior archaeologist Dr James Robinson said it was "not unusual" for kōiwi tangata to emerge after stormy weather.
Anyone who found them should record the site and appearance, and contact police, the closest marae or Heritage New Zealand.