New analysis of the DNA of mānuka from Aotearoa and Australia has shown they are different with researchers going as far as recommending the two plants should be called different species.

The debate about mānuka has been ongoing for years with the New Zealand industry fighting to trademark the term so that only honey from here can be dubbed mānuka.

The Australian industry fought back saying its honey can also be called mānuka as it comes from the same species of tree - Leptospermum scoparium.

Now researchers from Plant and Food Research have analysed 2000 variable DNA markers called 'SNiPs' (single DNA letter changes) in the DNA from each plant from both New Zealand and Tasmania.

They found strong genetic differentiation between Aotearoa New Zealand and Tasmanian L scoparium populations.

"These findings confirm that the Tasmanian populations are genetically distinct from NZ populations, which provides evidence that they should be recognised as an endemic Australian species separate from L scoparium, and subsequently L scoparium be treated as endemic to NZ," the research paper said.

Mānuka Charitable Trust chair Pita Tipene said the research provided further evidence of what the group had been saying all along - that Mānuka is a recognised taonga (treasure) under the Treaty of Waitangi, and its honey can only be sourced from and produced in Aotearoa New Zealand.

"Mānuka is a Māori word and tree that belongs to us. The expropriation of the name 'Mānuka honey' to a plant or natural product from outside Aotearoa New Zealand is taking the identity and associated epistemology of our culture, our knowledge and what we know and believe."

Last year The Intellectual Property Office of New Zealand rejected The Mānuka Honey Appellation Society's bid to trademark mānuka.

But Tipene said the new research would help with similar trademark cases in the UK and EU.

Funded by Te Pitau Ltd, the operating arm of the Mānuka Charitable Trust, Plant and Food Research and the Department of Conservation, the research was peer reviewed by three independent international scientists.

This story was originally published by RNZ