Killing one native species to benefit another is believed to be almost without precedent, and is dividing Maori and conservationists.
Information passed to the Greymouth Star, dated September, shows the Department of Conservation and the trustees of the Maori-owned islands agreed the birds would be killed and in some cases 'culturally harvested' (eaten).
However, DOC said yesterday its staff and the trustees were still in consultation.
South Westland area manager Jo Macpherson said "every effort is being made to find a suitable solution to the weka issue on the islands".
DOC has recommended all weka be removed from the two islands to save from extinction an endemic skink, gecko and leech.
It says other ground nesting native birds and invertebrates would also benefit from getting rid of the weka.
But Open Bay Island owner and Te Runanga o Makaawhio member Jackie Douglas said the trustees had not consulted the owners.
"As far as utilising these weka as a cultural harvest - the 'final solution' having been applied - and these birds ending up in someone's tuckerbox, is repugnant," she said.
"It is difficult to understand why tangata whenua Maori, as guardians of this (area), in the event of a mooted cull, would support such a radical plan of annihilating native birds we should be protecting.
"You might not want them in your veggie garden, but weka are an invaluable addition not only to our environment, but to our national heritage."
Ms Douglas said most owners were completely unaware of DOC's proposal to cull. The weka should be liberated on the mainland in South Westland, Ms Douglas said.
However, Ms Macpherson said weka had eaten the eggs and chicks of Fiordland crested penguins, as well as the seabirds prions and titi (muttonbird).
Reports in 1997 and 1998 found they were also believed to be responsible for severely reducing numbers of the critically threatened lizards and leeches.
In a recent survey of the Taumaka skink, only three individuals were found and the unique Open Bay Island leech had not been seen for 15 years, she said.
Weka were believed to have been introduced on different occasions to the islands in the early 1900s.
Ms Macpherson said genetic analyses suggested the birds had come from both the North and South islands, which meant they could not be released on the mainland.
Until now, the only place where the legal harvest of weka can occur is on the Chatham Islands and on some islands around Stewart Island.
The Greymouth Star understands the proposal has resurfaced over the years but each time was rebuffed by the runanga, in the absence of a trust, which was only formed last year.
The island is owned by hundreds of Maori, mostly members of Bruce Bay-based Te Runanga o Makaawhio.
Chairwoman Sister Tui Cadigan said it was a matter of balance. "(DOC) found the weka that were there to be an extremely strange species." Former Forest and Bird president Gerry McSweeney, who runs a lodge near Haast, recognised the dilemma but said it was about setting priorities.
The weka had been introduced to the island and were not endemic to it.
"I liken them to New Zealand's Galapagos Islands, you've got this limestone way off the Coast with lizards, and it's a paradise for penguins." NZPA GMS WGT kk
