Four men have been arrested and police cannot rule out further charges.

Four people have been arrested and more than 4000 cannabis plants were seized in a major police drug operation in Northland.

Last Thursday, more than 20 police, executed a search warrant at a property on Oturei Settlement Rd, near Aratapu.

Five glass houses filled with cannabis plants, including one which was more than 60 metres wide was located at the property by police.

Four men aged between 20 and 45 have been charged with cultivating cannabis and Police could not rule out further charges as the operation is ongoing.

Detective Senior Sergeant Geoff McCarthy said the cannabis cultivation operation was sophisticated and well established and the plants ranged in size from seedlings through to mature plants approximately 2.5 metres high.

"This is one of the most significant cannabis seizures Police have made in the Northland District for a number of years.

"There can be little doubt the cannabis being cultivated was destined for supply throughout New Zealand," McCarthy said.

McCarthy said the operation highlighted police's commitment to reducing the demand for cannabis and disrupting the supply chain.

"This is a great result for our communities who in the end suffer from the effects of drugs and organised crime," he said.

The four men will appear at Whangarei District Court next week and police could not rule out further seizures or arrests.