Police have seized hundreds of thousands of dollars worth of synthetic drugs after swooping on 10 Christchurch properties.
Police carried out search warrants at 10 addresses across Christchurch in the past two days and arrested five people.
A 31-year-old man has been charged with supply, possession for supply and unlawful possession of a firearm.
A 27-year-old man was charged with possession for supply, a woman and man both in their 20s were charged with supplying psychoactive substances and a 29-year-old woman was charged with unlawful possession of a firearm.
Detective Senior Sergeant Jason Stewart said the large scale operation stopped the drugs from reaching the black market.
While nationally there were fewer people using synthetic drugs, there was still a strong criminal market for them in Canterbury, he said.
Those charged have either appeared or will appear in the Christchurch District Court in the next two weeks.