A large quantity of class A drugs was also recovered by police.
The covert operation was a prime example of police collaboration, said Detective Inspector Greg Cramer from the National Organised Crime Group.
"The extensive assets generated by a small group through the sale of methamphetamine will have come at a huge cost to those who can least afford it.
"A sophisticated network has been dismantled and a clear message has been sent to those engaged in this predatory behaviour.
"If you are involved in the sale and distribution of illegal drugs you will be held to account, and have your assets seized."
Manawatu Organised Crime Group officers, National Organised Crime Group officers from Auckland and Asset Recovery Unit from Wellington attended.
Police urged the public to contact them if they noticed people accumulate wealth or assets without any legitimate means.
Anyone who had information about drug-related offending could contact police on 105, they said in a statement.
Otherwise, the public could contact police anonymously with confidence by calling Crimestoppers on 0800 555 111.
A number of people had been charged in relation to the seizures and were due to appear in the Palmerston North District Court over the coming days.
Two were due to appear today:
• A 42-year-old man charged with possession of methamphetamine and cocaine for supply, participation in an organised group, and money laundering.
• A 27-year-old woman charged with possession of methamphetamine for supply,
participation in an organised group, and money laundering.
Three others were due to appear in court tomorrow:
• Two men aged 42 and 37 charged with participation in an organised group, and
money laundering.
• A 36-year-old man charged with possession of methamphetamine for supply.
Three further people were due to appear next week:
• A 34-year-old woman, a 44-year-old man, and a 33-year-old woman charged with
money laundering.