A further seven unrelated search warrants were executed during the course of the two days.
Five Manawatü people in total were arrested and charged as part of the operation:
- 41-year-old woman was charged with importing psychoactive substances
- 34-year-old man charged with possession of cannabis and methamphetamine
- 22-year-old man charged with breach of bail
- 28-year-old man charged with possession of cannabis
- 42-year-old man charged with cultivation of cannabis
All five will appear in the Palmerston North District Court.
Customs investigations manager Maurice O'Brien anyone attempting to import and distribute these dangerous drugs would be targeted in furture.
"This operation is a great result for both agencies but more importantly for our communities who will not suffer the effects of these hazardous substances," he said.
"We have all heard and some of us have seen the devastating effects that synthetic cannabis products can have on people. Working together with the community is important and that's where information provided by the public can help us combat drug production and manufacture."
Mr Thompson said anyone with information about drug cultivation, manufacture or supply rings should contact their local police.
Alternatively information can be provided anonymously via Crimestoppers on 0800 555 111.