The agency said the large-scale home kill operation was in the greater Auckland region.
Home kill is slaughter and butchering of your farmed animals to be eaten by you, your family and household, farm workers employed and their family and household.
It is not subject to the same regulatory controls that apply to meat from a supermarket or butcher.
Simon Anderson, MPI Northern region investigations manager, said officers executed six search warrants in the west and south of the city.
"Officers seized a refrigerated container, a truck, unregulated meat, and a large amount of food processing equipment. This was a large-scale, sophisticated operation involving more than 100 customers."
Anderson said in the lead up to Christmas illegal home kill operations are, traditionally, more prevalent.
“Meat being sold directly from a farm to the public is a strong indicator of unlicensed activity,” he said.
"If we receive information about these kind of operations we will shut them down and prosecute the people making money from selling potentially substandard product. There’s a very serious public health component to our interest in ensuring people comply with the law.
"Individuals involved in illegal activity face a prison term of up to five years and a fine of up to $100,000 – it’s just not worth it."
Revamped food safety website
Meanwhile, a revamped food safety website about the joint Australian and New Zealand food regulation system has been launched.
Dr David Gillespie, assistant minister for rural health, launched the website at the Ministerial Forum on Food Regulation meeting in Brisbane.
“Food regulation is a complex system that involves all levels of the Australian and New Zealand governments. For some time the Australian Government Department of Health has hosted a food regulation website which, following feedback from stakeholders, has been extensively improved to make finding relevant information easier, and more accessible.”
The site is aimed at industry, associations and public health groups and consumers.