He told Hawke's Bay Today it's an ongoing operation to "stamp-out" illegal drugs which are a known problem in the Northern Hawke's Bay town and area, and are linked to other crime, including shootings.
The latest warrants involved members of Mongrel Mob Mongrelism, one of several chapter names in the town.
These arrests come after recent gang violence in Wairoa which led to the arrest of a Mongrel Mob Aotearoa patched member for the stabbing of a rival gang member at the forecourt of the town's Z Energy service station on December 23.
No further details were available relating to the stabbing, but there had also been two shootings at gang addresses in the area on December 23-24, neither with any reported injury.
In September eight people were arrested, and along with methamphetamine police seized firearms and cash, and restraining orders were placed over seven homes and six vehicles, including a jetski, an excavator, a Mini Cooper and a Harley Davidson motorcycle.
Police said at the time more than 60 police staff had been involved in that six-week operation set up to target the supply of methamphetamine, which has a maximum possible penalty of life imprisonment.
They said eight properties had been searched. Those arrested had links to the Mongrel Mob, with one a male patched member.
Moorhouse said after the latest bust police are "very pleased" to prevent such large amounts of methamphetamine from hitting the street, and added: "Wairoa as a community has clearly suffered from the impact of gang violence and the distribution of this highly addictive drug."
Wairoa Mayor Craig Little, whose urban-rural district has about 9000 residents, about half in the town of Wairoa, said it's :"great work" that the police have been doing, but he is perplexed by the methamphetamine plague and its related gang issues, and the role of the Mongrel Mob chapters.
"I think we're up against a brick wall," he said. "I'm pleased the police are getting a bit tougher, there are a lot of flash toys out there, and there's probably only place that is coming from," he said.
He said it was particularly worrying that young people in the town could be attracted into the network, and that shootings and violent incidents were happening in public places.
Charges in both operations have included possession of methamphetamine for supply, which carries a maximum possible penalty of life imprisonment. Under current sentencing regimes, possession of between half-a-kilogram and 2kg could attract a sentence of 10 years to life.
The biggest methamphetamine-dealing sentence imposed in a Hawke's Bay court was the 13 years imprisonment for that of Shane Thompson, who at the age of 31 and known in Auckland as a high-class poker player, was arrested on 14 counts of supplying methamphetamine and five each of possessing and conspiring to deal the Class-A drug, related to a lead role in supplying at least 4.2kg of meth in Hawke's Bay.
He was sentenced to 13 years in jail and cannot be considered for parole until early 2025.
In one of the more significant methamphetamine cases in New Zealand courts, a High Court judge in Auckland sentenced Tai Fi Chiu, Yiu Wai Chang, Li Hao, Chi Wa Leung, Ricky Tat Choi Leung and Zhi Zhao Tan to terms ranging from the 16 years for 57-year-old Chang to Ricky Leung's 27 and a half years (with a minimum of nine years).
It related to the elaborate shipping of more than 250kg of methamphetamine from China, with street value estimated at the time to be possibly more than $67 million, and an importing ring uncovered after Customs and police started tracking Ricky Leung's arrivals and movements in New Zealand in 2016.