Members of Parliament have been told that legislation on managing offshore activies such as drilling and mining, is not consistent with international law on protecting the marine environment.
The Local Government and Environment Committee on Thursday heard submissions on a bill about the Exclusive Economic Zone and Continental shelf.
The bill's stated aim is to achieve a balance between economic development and environmental protection in those areas.
But Parliamentary Commissioner for the Environment Jan Wright said that making a judgement about such balance is not in line with the International Law of the Sea.
That law says natural resources can be exploited but there is an obligation to do so while protecting and preserving the marine environment.
Commissioner Wright said it would be wrong for activities to be approved just because it's decided that its economic contribution would outweigh any adverse effects on the environment.