I looked at the lizard; the lizard looked at me. It was dopey and confused; I was utterly horrified. Like all Kiwi travellers, I've had it drummed into me that I must not bring back from overseas anything that may threaten our agricultural economy. So, before returning, I scrub my shoes, pick grass seeds off socks and, at the airport, dutifully declare even lollies and chocolate.
Yet here I was, back home in my bedroom after a week on a Pacific island, my suitcase open on the bed, eye-to-eye with a Cook Islands gecko.
Fortunately, August in Auckland is chilly enough to bring a tropical reptile to a standstill, and it was easy to flick the lizard into a plastic bag while I googled MAF.
Now called MPI (Ministry for Primary Industries), its helpline number took me to a reassuring voice.
The primary concern was to persuade me to euthanise the lizard by popping it into the freezer. "Are you all right about that? It won't feel a thing, it'll just go to sleep," the voice reassured me.
With the weight of New Zealand's biosecurity on my shoulders, I had no qualms about dispatching my gecko, cute though it was, and it was duly sent off on its long sleep while I waited for the promised courier.
The pack he brought meant business: a litre-capacity screwtop jar, a pair of disposable gloves and a paper towel soaked in preservative. It seemed a bit over the top for a dainty 10cm lizard, but I wrapped its frozen corpse and sent it to Motueka in the supplied bag.
Within the week, I had the report back from Tony Whitaker, MPI's herp man, responsible for inspecting found reptiles and amphibians: my hitch-hiker was an immature female Asian house gecko, Hemidactylus frenatus, and unlikely to survive in New Zealand's climate.
According to MPI's William Minchin, this was typical: 83 per cent of accidental importations are lizards, and 58 per cent of those are house geckos, which are widespread throughout Asia, chirping on the ceilings of hotel rooms from Taiwan to Tonga, Africa to South America.
Most of them arrive in shipping containers from the Pacific islands, only 12 per cent in the baggage of tourists like me, whose reactions range from delight and interest to fear and revulsion; clearly the reason for the disposable gloves in the return pack.
Fortunately, most people understand the importance of biosecurity and comply with the instructions to dispatch the creatures.
After lizards, the creature most commonly found in people's belongings is the reviled cane toad, scourge of Australia, which likes to hide in shoes left outside.
In 2009, this was how one arrived in Queenstown, hopping out of the tramping boot of a visitor from Cairns who was preparing to walk Milford Track. The boots had been declared at the airport biosecurity check, but the toad was undetected by the inspection: rather more scandalous than the MPI officers missing a tiny lizard skeleton in the X-ray of my suitcase in Auckland.
A spokesperson at the time was reported as saying, "In the light of this incident, they'll probably be looking [in boots] a bit more carefully."
Hearing that a woman had found a 2cm gecko in her sponge bag the same week I found mine, I wondered what hope there was of detecting such tiny creatures inside crammed suitcases, especially since baggage is not now routinely x-rayed on arrival.
William Minchin replied: "Airport x-ray machines have limitations in picking up herps. But it is important to note that they are only one of the tools that the Ministry for Primary Industries uses to check passengers for biosecurity risk. Our quarantine officers speak to every arriving air passenger and use a range of other tools, for example, physical searches, risk analysis of passengers, detector dogs, public education campaigns, amnesty bins, declaration cards and infringement fines.
"Moreover, we are constantly evolving our tools to protect New Zealand from biosecurity risk."
The last line of defence, however, is you and me, looking for intruders as we gloomily unpack our bags at the end of a holiday. Be alert and, if you find one - gecko, frog, toad, snake, spider, beetle - catch it and ring the MPI biosecurity helpline: 0800 809 966.
• 83 per cent of accidental importations are lizards
• 58 per cent of those are house geckos
• 12 per cent arrive in tourists' baggage
• If you find one in your luggage, phone the MPI biosecurity helpline on 0800 809 966