More than $300,000 in buried cash and $175,000 in methamphetamine was found at a police search of a property in Napier last week.
A two-and-half month operation had focused on a man who allegedly supplied methamphetamine to various dealers around Hawkes Bay, Gisborne and other parts of the country, Detective Inspector Mike Foster said.
A 53-year-old man has since been arrested and appeared at Napier District Court charged with supplying methamphetamine.
He was granted interim name suppression and remanded in custody until his next court appearance on November 12.
About 25 police staff were involved in the operation, including the Hawkes Bay Armed Offenders Squad and the Specialist Search Group, Mr Foster said.
In a search of the man's 15 acre farm on the Napier-Taupo Rd last week, as well as a neighbouring property, $175,000 worth of methamphetamine and two pistols were found, he said.
He said police also found $310,000 in cash buried in the ground near the property.
"This was a difficult operation, not least because of the rural location of the property, but we are very pleased with the results," Mr Foster said.
"We believe the arrest will make a significant dent in the supply of methamphetamine not just in the Eastern District, but to other parts of the country.
He said methamphetamine was a major driver of crime, particularly burglaries, and police were constantly dealing with offending that had its origins in drugs.
"It's well-known that a lot of burglaries and dishonesty crimes are linked to the offender's need to get drugs, often to support a habit. "Methamphetamine is a major player in the criminal community and we are determined to bring those responsible to justice."
Police urged the public to report any suspicious activity that may be related to drug offending and anyone with information could contact Crimestoppers on 0800 555 111.