Queenstown Lakes District Council communications manager Michele Poole said a council arborist had inspected the trees.
"What has been done was not sanctioned, recommended or carried out by [the council] or our contractor," Ms Poole said.
"Street trees are a public asset, paid for and maintained using public funds. The council plants them to benefit the wider community by enhancing the environment and we manage them for the benefit of all.
"Topping a tree ... not only destroys the natural shape of a tree, it allows wood decay fungi and insects into a healthy tree, compromising its future health. Our arborist will be assessing the trees with a view to whether further action is warranted," Ms Poole said.
In 2012, Meadowstone residents pruned, without permission, about 10 council trees they considered were getting too big.
After negotiations with the council, the residents paid for the trees to be replaced with more suitable species.
