Two kilograms of cannabis has been seized in drug raids targeting the entire town of Nimbin in northern New South Wales.

Officers arrested eight people after allegedly finding the drugs in a cafe and bookshop in the village.

Further raids uncovered cannabis plants at a property in nearby Jiggi.

Police allege the stores were being used to sell a range of drugs like cannabis and LSD.

More than 70 police officers carried out the raids after a six-month investigation which will continue with sniffer dog patrols.

Police Commander Greg Martin said stamping out Nimbin's well-known drug trade would require a much bigger effort.

"It would be a significant police presence every day of every week of every year until the demand side of the equation lessened," he said.

"Because that's what it's all about, supply and demand.

Police say 4.5 kilograms of high-grade cannabis was found during a drugs raid at Nimbin. ( Supplied: NSW Police )

"We have two buses that go there every day from the coast... with overseas tourists who think they can go there and buy drugs legally.

"We know that it won't be long before it's business as usual, but we're not going to go away."

Commander Martin said the operation had dismantled a criminal group that police alleged was responsible for supplying significant amounts of drugs throughout the Nimbin area.

"As long as it's the law that these drugs are illegal, we'll be enforcing the law," he said.

"It's not just about cannabis - we're not just picking on a few old hippies, which is a common issue that is put to us.

"It's about all these other drugs, and it's about the effect it has on the community."

He said 70 police were needed for safety reasons and to comply with risk assessments.

"The way things work these days with risk assessments and everything and conducting three simultaneous search warrants in separate locations, you need that many people," he said.

Police expect to make further arrests.