Trends of clandestine laboratories manufacturing methamphetamine in New Zealand between 2009-2021: Evolution, enforcement, legislative, and COVID-19 effects.

The most common method of domestic methamphetamine manufacture encountered in New Zealand is the hydrogen iodide (HI) reduction of pseudoephedrine/ephedrine. While the overall method used to manufacture methamphetamine has remained consistent, the processes and chemicals utilized have evolved. Understanding the reason for any changes to methamphetamine manufacturing trends can assist jurisdictions with predicting the potential effects of enforcement and legislative initiatives.

Establishing likelihood ratios for evaluating opposing propositions concerning the activity causing methamphetamine contamination: Smoking or manufacture?

In New Zealand, concerns have been raised over the presence of methamphetamine contamination in households, especially when the activity causing the contamination is unknown. The cause of contamination is also a contentious issue in clandestine laboratory cases concerning charges in relation to "Use of Premises" (Section 12: Misuse of Drugs Act 1975, New Zealand). Regardless of the cause, other than scientific opinion, there is currently no analytical technique that can satisfactorily address the provenance of methamphetamine residues.