The police say the use of methamphetamine, or P, is not decreasing, despite Customs' figures showing fewer pseudoephedrine tablets are being seized at border controls.
So far in 2011, Customs has intercepted nearly two million pseudoephedrine tablets, the main ingredient in making P - compared to nearly 4.4 million last year.
The number of tablets seized over the past six years peaked in 2009, when nearly 5.4 million were found.
So far this year 438kg have been intercepted in 465 incidences. Last year 978kg were seized in 788 incidences.
Police Assistant Commissioner of Investigations Malcolm Burgess, says while that is cause for cautious optimism, in reality use of the drug hasn't decreased.
He says people are finding more inventive ways to both smuggle and manufacture it. Mr Burgess also says there's evidence of a slight increase in ecstasy and cocaine use.
And the managing director of the anti-drugs consultancy Methcon Group, Dale Kirk, says the amount of ready-made methamphetamine being seized by Customs is increasing.
Mr Kirk says this suggests that while production of the drug here may be reducing, usage is not.
"I think we're drawing a long bow if we say that, just because seizures of pseudoephedrine have reduced in the last 12 months, that that equates to a reduction of meth use in the country. That would be a naive thought-process to take."
He also says people have found ways to make P without using pseudoephedrine.
However, Massey University's Dr Chris Wilkins, the lead researcher on the annual Illicit Drug Monitoring System study, is more positive.
He believes the drop in border seizures is partially due to the extra resources being poured into combatting P, along with the decision to increase the status of pseudoephedrine to a class C drug.
