Cambridgeshire police shut down cannabis factories in Wisbech, Doddington near March and Peterborough, seizing more than 1,000 plants with a street value of £1million.
Police carried out warrants on February 1 in Woodston, Walton, Bretton, Gunthorpe, Fletton and another in Stamford, Lincolnshire.
Eight people were arrested on suspicion of being concerned in the production of cannabis.
The cannabis plants seized were worth up to £454,440.
“Officers seized more than 500 plants worth nearly half a million pounds after shutting down four cannabis factories in Peterborough,” said a police spokesperson.
In Peterborough on February 1, 24-year-old Erjon Llusha of Peake Close, Woodston, has been charged with production of cannabis.
A 29-year-old man and a 26-year-old woman from Peterborough, and a 47-year-old man from Stamford have been bailed whilst investigations continue.
Four men aged 21, 23, 29 and 33 have been handed over to Immigration services.
Police were busy again yesterday (Saturday) in Wisbech where the Wisbech Neighbourhood Policing Team and the Fenland Response Team closed two cannabis factories in the town.
The first was at an address in Clarkson Avenue in which 228 plants were seized.
The second was at an address in Seabank Road in which 259 plants were seized.
“Enquiries into both addresses continue,” said a police spokesperson.
Last week, the March neighbourhood policing team carried out a warrant on a house in Wimblington Road, Doddington.
67 cannabis plants worth up to £56,280 were found in various rooms throughout the house, along with boxes of new designer clothing, suspected to be stolen goods.
A 19-year-old woman from London was arrested on suspicion of cultivation of cannabis, abstracting electricity, and handling stolen goods.
She has since been bailed whilst enquiries continue.
A 32-year-old man has been charged with cultivation of cannabis and is going through the court process.
Sergeant Paul Delmer, of the Peterborough Neighbourhood Support Team, said: “Thanks to the hard work of our officers, we were able to shut down multiple cannabis factories across the city.
“I would like to encourage the public in helping us locate these factories by looking out for the signs and reporting any concerns to us.”
If you suspect drug activity in your area, report it to Cambridgeshire police online www.cambs.police.uk/report