"Illicit drugs not only cause millions of dollars of social harm each year but they destroy lives and relationships, and other crimes such as theft and burglary are often committed to fund drug habits," he said.
"Every police officer plays a role in reducing drug crime, from early intervention with our officers in schools, to major operations targeting organised criminal networks."
Mr Mastrovich said police relied on information from the public to stem the flow of drugs in Wanganui.
"Communities are our eyes and ears and we need them to report to police locations of drug manufacture, cultivation or dealing, and any suspicious activity."
NZ Drug Foundation executive director Ross Bell said drug use, manufacturing and trafficking was a big problem.
"Surveys done by the Ministry of Health routinely show that New Zealand has some of the highest illicit drug use in the world so it would make sense, therefore, that that would be reflected in our crime stats around possession."
Mr Bell said the key to stemming the drug problem was to curb demand.
"The law enforcement approach to drugs, which is hoping the police and the court will get rid of these problems, is a really limited and narrow-minded way of addressing the drug problem," he said.
"What we argue is that if there is demand for drugs, then criminal gangs will find a way to supply that demand, so in this country we need to switch our attention on to reducing the demand for drugs.
"We will do that through prevention, good education, appropriate treatment for people who are in trouble."
Mr Bell said police were becoming smarter in the way they handled minor drug use.
"In the drug area we have seen greater use of alternatives to punishment and that includes the police diversion scheme and in the past few years they have also been running the pre-charge warning scheme."