Up to 100 Ngai Tahu families could be stripped of their mutton birding rights as descendants of a small group of rangatira use the courts to bar access to a group of southern islands in Foveaux Strait.
The group, led by Lowana Clearwater, says only direct descendants of the 15 rangatira named in the 1864 Rakiura Deed of Cession should be allowed to collect mutton birds from 18 islands excluded from the sale of Stewart Island.
Mrs Clearwater successfully challenged a succession which would have confirmed the right of Tommy Ashwell to continue birding on Taukihepa, where he has built a house.
Mr Ashwell, of Invercargill, told Waatea News the precedent will be used against other families whose rights stem from Maori Land Court decisions early last century.
He says the 15 rangatira signed on behalf of the whole tribe, not to claim rights only for their own children and grandchildren.
Mrs Clearwater has refused to comment.
