Every member of Comancheros Christchurch chapter arrested in ...

Every member of the Comanchero's Christchurch chapter was arrested and drugs, cash, firearms and motorbikes seized. Photo: Police/supplied

Police have arrested every member of the Comancheros gang's Christchurch chapter in drug bust.

5kg of class A drugs, 11 firearms, ammunition, about $250,000 cash, 11 vehicles, and an Auckland property were also seized, police said.

It was the culmination of an eight-month investigation, called Operation Avon, by the National Organised Crime Group and Canterbury Police.

Photo: Police/supplied

Police alleged the gang organised for drugs and cash to be relayed between Auckland and Christchurch every few weeks.

Detective Inspector Darrin Thomson said police believed $15 million worth of drugs were moved between the North and South Island.

"Our investigation showed that they were bringing from the North Island down to South four kilos a fortnight, and to give you some idea that's $1.4 million street value every fortnight," Thomson told Checkpoint.

"The prosecution will allege this groups is responsible for supplying more than 60 kilos of Class A drugs during the investigation phase... that's over two million doses of those Class A drugs into our community and that's just horrific," he said.

"Operation Avon is holding those responsible to account following a meticulous investigation and coordinated response.

"Pivotally, arresting every member of the chapter will put an end to their unwanted presence in our Christchurch community."

Photo: Police/supplied

Seventy warrants were executed in Christchurch and Auckland on Wednesday.

Eighteen men, aged between 18 and 55, were arrested and have appeared in court in Christchurch and Auckland; 12 were in Christchurch and six were in Auckland.

Charges included participating in an organised criminal group, conspiracy to supply methamphetamine, and conspiracy to supply cocaine. Further charges of money laundering and drug dealing were being considered.

Detective Inspector Thomson said the drug offending involved methamphetamine and cocaine.

"These groups have no hesitation in peddling drugs and accumulating vehicles and property, with no regard for the destruction they cause in everyday New Zealanders' lives.

"We have no doubt that this disruption of the Comanchero gang will have a positive impact on the drug supply chain across the country."

Photo: Police/supplied

Thomson said the arrests would make a "large dent" in the spread of drugs across the country.

"Our intelligence said that this group was responsible for the majority of Class A drugs coming into the area."

"We've certainly disrupted this supply chain and the amounts that we're talking about is over $50 million in terms of harm, so if you can think we've stopped that in its tracks now I think the community will be far safer."

It was a "lot of hard work" to get to the point of the arrests, Thomson said.

"A lot of specialist groups involved, a lot of co-ordinating and planning, so it really comes down to investigative techniques and making sure we know where they are at the time when we're going to be going through the doors."

Thomson did not know how many patched members remained in the country.

Police said the Auckland property and vehicles seized were worth $1.9 million and the class A drugs seized were worth millions.