The 30cm potted plant was detected by biosecurity staff as the well-wrapped package passed through the x-ray machine at the International Mail Centre in Auckland this week.
The diminutive tree was among the stranger seasonal seizures this year, with biosecurity staff more accustomed to intercepting hamper goods in the lead-up to Christmas.
Ministry for Primary Industries northern passenger and mail manager Craig Hughes said he sometimes felt like the Christmas grinch.
But border staff had an important job to do, and they usually tried to get in touch with the sender or recipient, offering to return or treat the goods if possible.
Mr Hughes said the amount of mail increased dramatically every Christmas and there were some typical seasonal finds.
"Often it's Christmas-related, either small goods like meats, pates and salamis, also fir trees or pine trees - usually clippings, but not the whole tree.
"Of course all of that is not allowed in the country because it's high risk."
Mr Hughes said baked goods, like Christmas cakes or mince pies, could be allowed in if they met standards. Commercially packaged goods were usually fine, but home baking might not be.
Despite such a wide assortment of goods being fairly typical, biosecurity staff were still shocked to see the live potted tree.
"The quarantine inspector working the x-ray machine thought, 'what the heck?"'
Mr Hughes said the tree, of unknown species, had fared well in its journey over from the UK.
"It's fully potted and rooted, and it's in very nice damp soil. It only takes a few days to come across nowadays, and it's all wrapped up nicely."
But there was no way the tree would be allowed into the country because it may have been harbouring fungi or insects in its soil, roots or foliage.
The biggest concern was a fir tree-killing fungus that was rampant in Britain and North America at the moment.
"They're talking about a fatality rate of three out of four for their Christmas tree production - it's massive over there, so you can imagine if something like that came to New Zealand."
The tree's sender has been offered the choices of having it destroyed or returned to the UK.
- by Matthew Backhouse of APNZ
