TWO people were due to face court on Friday after police found cannabis plants and hydroponic equipment at several Hunter properties.
Emergency services were called to a property on First Street at Weston about 9am on Thursday after reports it had caught fire.
Fire and Rescue NSW extinguished a blaze a short time later. When they inspected the property, they found a hydroponic set-up.
Hunter Valley Police District officers subsequently established a crime scene and began investigating.
Their inquiries led police to arrest a man and woman at a property in William Street at Abermain.
Both the 52-year-old man and 54-year-old woman were identified as unlawful Australian citizens, police said.
They were taken to Cessnock police station as officers searched the Abermain and Weston properties on Thursday afternoon.
On Friday, officers raided a third premises in Mount View Road at Cessnock.
Police will allege they found more than 500 cannabis plants, several kilograms of cannabis and drug paraphernalia.
The 52-year-old man has been charged with cultivate prohibited plant larger than commercial quantity, possess prohibited plant greater than indictable quantity, and deal with the proceeds of crime.
The 54-year-old woman has been charged with cultivate prohibited plant larger than commercial quantity, and possess prohibited plant,
Both were refused bail.
Investigations are ongoing.