Police have made a number of arrests after shutting down four commercial scale methamphetamine labs in the wider Waikato area.
Police targeted five addresses across Matamata, Waharoa and Morrinsville, seizing commercial quantities of methamphetamine manufacturing chemicals and equipment.
Three men aged 35, 56, and 59 and one woman, 40, have been charged with manufacturing and supply of methamphetamine and will appear in the Hamilton District Court over the coming weeks.
Detective Inspector Graham Pitkethley said information provided by the public about unusual or suspicious behaviour helped them get an idea about the manufacture, distribution and supply of drugs.
He said labs like those found were extremely dangerous and police encouraged people to advise them without doing their own detective work.