Eleven people have been arrested and 100 charges laid, after police raided homes across the Wairarapa this morning.
Over 50 Wellington police staff executed 10 search warrants at different addresses, targeting the supply of the Class A drug methamphetamine.
The 11 arrested include men and women, ranging from their late teens to late fifties.
Police say the 100 charges include drug dealing, money laundering, and participating in an organised criminal group.
Acting Wairarapa Area Commander Inspector Scott Miller said those arrested were "closely associated".
"Today's arrests are the result of a medium-term drug operation specifically targeting a tight-knit group in Masterton who police allege have been supplying methamphetamine to a large number of Wairarapa people, including young persons."
Officers have seized assets including real estate, vehicles, and cash.
"In addition to putting these people before the courts, we are committed to targeting and restraining property and assets derived from crime," Miller said.
"Those involved in distributing drugs must understand that not only do they risk imprisonment, but they also risk the forfeiture of their property.
"One of the more alarming features of this type of operation is the intergenerational offending that is uncovered.
"There is a long-term iimpact on the younger generations, who are facing serious criminal charges that will affect their future and their own families' future."
Miller said one of the problems with meth was that it also drove a spike in associated crime as users tried to fund the habit, including burglary, theft, and vehicle crime.
"Often when methamphetamine dealers are removed from a community it gives users of drugs some time and space to reflect on the impact that the drug has on their lives, health, and the disruptive effect on their families with the impact spreading over the wider family dynamic."
Miller said they would now be speaking to a number of people identified through the investigation, including those who would not face charges but may be trapped in the drug-using lifestyle.