A group of Waikato Maori are seeking a legal injunction to stop the sale of Mighty River Power.

They are also considering charging the Waikato-based energy company rent - backdated - for the three hydro dams already on the river, 3News reported last night.

The people of Pouakani - near Mangakino - claim to own a section of the Waikato riverbed.

The Crown had had dominion over the riverbed for more than 125 years but a Supreme Court ruling last month confirmed "the riverbed adjoining the Pouakani lands is not vested in the Crown" and opened the way for the people to lay claim to it.

Pouakani leader Tamati Cairns told 3News selling Mighty River Power before the iwi claim was dealt with was like Government confiscation. "They're confiscating my right as expressed in the Treaty of Waitangi."

The area of the Waikato riverbed under claim houses three Mighty River Power dams: Maraetai I, Maraetai II and Waipapa.

They have been there for almost 70 years, which, Mr Cairns said, could mean back-rent or compensation.

He told 3News that, after fighting for so long, the community had no choice but to seek an injunction on the Mighty River Power sale - either with the Maori Council or on its own.

"If you have a history that connects you to that, you have a responsibility to take action."

Prime Minister John Key has been staunch on his stance that no-one can own water but he was not sure about riverbeds.

State-owned Enterprises Minister Tony Ryall last night told the Waikato Times the Crown was confident of its position on asset sales and that the minority sell-off would "have no adverse impact on the interests and rights of Maori".

"Court challenges have always been a likelihood, and we will work our way through any, step by step."

- © Fairfax NZ News