Whakatāne Police have executed several search warrants in Te Teko targeting the manufacture and supply of the psychoactive substance drug commonly known as synthetic cannabis.
Detective Sergeant Paul Hipkiss said the warrants were subsequent to an earlier warrant executed in the town at a senior Mongrel Mobgang member's address, who police suspected was dealing methamphetamine.
A synthetic drug is made up of a smokeable plant material that has been mixed with a chemical compound.
The drug can either be a class A or C, the classification depends on what compound is used.
Hipkiss said on Wednesday police found evidence of tobacco being soaked in a psychoactive substance which was then dried and sold in zip lock plastic bags for between $20 and $30.
Large quantities of cash, synthetic drugs, chemicals, tobacco, cannabis and firearms were seized.
Three men and one woman ranging in ages from 25 to 61 were arrested and have been charged with drug and firearm offences.
Police expect to lay further charges once the drugs have been analysed.
"We will continue to target and disrupt this criminal offending and hold those to account who simply don't care about the harm they are causing in their own communities and who's primary motivation is financial gain," Hipkiss said.
"There is a clear link between drug use to all crime. It continues to be a major contributing factor to our serious crime investigations in the Eastern Bay."