The architect of the Resource Management Act, Sir Geoffrey Palmer, says a new environmental reporting system will only be truly independent if Parliament decides what is monitored.
The Local Government and Environment Select Committee is considering legislation to set up independent reporting of environmental data.
But Sir Geoffrey, who appeared before the committee as the Fish and Game Council's legal advisor, said as it stood, the topics would be decided by the Government and that was wrong.
"They cannot be independent if the bill in its present form proceeds because the ministers have the power to set the topic and that should not be the case. It should be for Parliament to set the topics that are reported on."
Sir Geoffrey said the select committee should suggest what topics needed to be covered and call for public submissions.
He saids new topics could be added without full legislation.