Agriculture Minister David Carter is rejecting claims by the Green Party that he tried to interfere in a matter that could potentially affect his farming operation.
The Greens have asked the Auditor-General to investigate a potential conflict of interest over a law change that replaces Canterbury's regional councillors with a panel of commissioners.
It also changes the process for getting rivers protected through water conservation orders.
The Greens say Mr Carter's farm, which takes water from the Hurunui River, could benefit if a proposed dam on the river is approved.
Mr Carter has rejected that and says allegations he tried to get opponents to hold off on an Environment Court process about the river are incorrect.
The minister says he was encouraging them to protect their position with the court but to also see if they could find a solution by consensus.