The Court of Appeal has reserved its ruling on whether a government ministry was being too lax to allow the export of rough-sawn swamp kauri.
In the High Court last year, the Northland Environmental Protection Society lost its claim that the Ministry of Primary Industries allowed the Forests Act to be breached by allowing the export of swamp kauri stumps in an almost raw state.
The society challenged the High Court decision in the Court of Appeal which heard argument from both parties last week before reserving its decision.
It had argued in the High Court that the stumps were being passed off as artworks and furniture, in breach of the Protected Objects Act and the Forest Act.
The stumps, roots and slabs often had only rudimentary embellishments to qualify as art or furniture, and thus get around the rules about exporting the raw material, the NEPS argued.
It disputed that swamp kauri "table-tops" without legs or with light surface carving could lawfully be exported.
But Justice Toogood ruled in the High Court at Auckland last year that ancient swamp kauri was not subject to the Protected Objects Act and its export could continue.
He said imposing extra restrictions would "create an oppressive regime restricting the removal from New Zealand, by ordinary travellers, of everyday products which have no
particular significance".
He also refuted the society's argument that buried swamp kauri was a fossil worthy of protection under the act, like kauri gum and scrimshaw whale bone.
Justice Toogood noted there had been historical concern around the export of kauri stumps but he was satisfied with MPI's system which he said had "progressively improved its procedures" since late 2011.