Detective Sergeant Ian McKinnon, of the West Coast Tactical Crime Unit, said Operations Scissor, Razor and Snip were an inter-district initiative targeting the sale and supply line of MDMA (also known as Ecstasy) in the West Coast region.
Four search warrants were carried out in Christchurch this week.
Drugs seized included MDMA, ketamine, LSD, cocaine, cannabis and steroids, with the street value of the MDMA and ketamine alone estimated to be about $70,000, he said.
Police also confiscated approximately $100,000 in cash and nine electronic devices, and were looking to secure more assets linked to the case.
A 26-year-old has been charged with several counts of Ecstasy-related offences and will reappear in court on June 5; a 24-year-old is facing LSD and Ecstasy-related offences and will reappear on June 7; a 28-year-old is facing multiple charges related to the supply and distribution of Ecstasy and will reappear on June 6, as will a 23-year-old on two drug-related charges.
Det Sgt McKinnon said police are searching for a fifth person.
Further charges were likely.
"Police are committed to cutting off the harm that these drugs cause in local communities by identifying and targeting those who manufacture and supply drugs such as MDMA and LSD," he said.
People were encouraged to contact police with information about any dealing or supply of illicit drugs in their community. Report via the 105 line or call Crime Stoppers anonymously on 0800 555 111.
