Many Maori believe the Treaty of Waitangi is too important to be put into a written constitution, Constitutional Advisory Panel co-chair Sir Tipene O'Regan says.
The panel recommends the Treaty be kept out if New Zealand adopts a single written constitution, which would govern the way residents live.
It received more than 5000 submissions and hosted 120 hui.
Sir Tipene, of Ngai Tahu, says putting the Treaty into written form is challenging because it is still subject to a range of interpretations.
Many Maori are anxious about putting it into a document that could potentially be changed by Parliament and take the view that, much like the American Declaration of Independence, it is too important to have in a constitution.
Sir Tipene says the main issue is how uninformed the country feels about these issues, and recommends more accessible information for the public.