Hawke's Bay iwi, Ngati Kahungunu, says it could potentially become an investor in the controversial Ruataniwha Water Storage Scheme, but only if changes are made to the dam proposal.
Ngai Tahu has pulled out as an investor because the Hawke's Bay Regional Council's investment company hasn't found a replacement for Trustpower.
The electricity company stepped away in March because of concerns the project was too risky and it wasn't satisfied with the potential return it might receive.
Ngati Kahungunu Runanga chair Ngahiwi Tomoana said if changes were made to the proposal to include strict environmental conditions set by a Board of Inquiry it could become a possible investor.
He said it would not support the plan in its current form.
Mr Tomoana said the tribe would not support what he described as a shonky or amateur prospectus - when crucial environmental matters needed to be taken in to account, as well as the welfare of Ngati Kahungunu and the wider community.
Earlier this month, the Hawke's Bay Regional Council asked for a month-long extension to allow the board of inquiry more time to consider comments on its decision to impose strict environmental conditions, which could have significant implications for farming communities.