A leading scientist is joining Wanaka people in asking Contact Energy to give back land no longer needed for a dam project.
Land along the Clutha River is set aside for hydro-electricity schemes that were shelved two years ago.
Contact Energy plans to sell some of the land to the Department of Conservation.
But Sir Alan Mark, a leading botanist, said the company has benefited from the increasing value of the land and it should be a good citizen and gift some back.
He said the land hosts unique plant and animal species that could be lost.
Contact said it is not fair to ask a commercial enterprise to give away its assets.
The company also said much of the land has been sold to the people who have leased it for years, so little will change.