Police believe they have smashed a major drug ring supplying the drug ice in the northern New South Wales town of Moree.

During a nine-month secret operation, local detectives from Strike Force Sassafra seized 300 grams of methylamphetamine, or ice.

It is an amount they say would make up at least 3,000 street deals, and would have an estimated street value between $500,000 and $1 million.

The operation culminated in the arrest of three local men aged 23, 24 and 34 after nine homes were raided in Ashley and Moree on Tuesday and Wednesday, with the public order riot squad called in.

The men were all charged with multiple offences including the ongoing supply of a prohibited drug and participating in a criminal group, with the older man charged with supplying drugs of a commercial quantity.

The three accused have been described by police as significant players in the town's drug supply.

Moree detective inspector Dave Silversides said the arrests were a huge breakthrough.

"This is a drug ring specific to the Moree region. We're not naive enough to think that this is the one and only line of supply into the area," Detective Inspector Silversides said.

"But we certainly believe this is a significant outcome for the community, significant outcome for the broader area."

Specialist resources used to bust large-scale ice supply

Local detectives made three arrests after a nine-month operation. ( Supplied: NSW Police )

The Moree-based Barwon Local Area Command used specialist resources, including the public order riot squad and a drug dog, to carry out the search warrants this week.

Police also seized other items including a boat, trailer, quad bike and motorbike believed to be proceeds of crime.

Detective Inspector Silversides said he was pleased with the outcome.

"The investigation team has worked tirelessly over that nine- month period, utilising various resources within the command but externally as well," he said.

"This is something we are extremely proud of. We believe that this will have a significant impact on the drug supply with the Moree area."

Strike Force Sassafra will be an ongoing cover operation, with further arrests to be made.

"At this stage we have not identified any drug labs in the area. The drugs that we have seized over that time have been coming externally into the Moree area," Detective Inspector Silversides said.

"We're working hard to identify lines of inquiry around how that drug chain comes into town."