Drugs worth £130million were seized by police in raids on 1,000 cannabis farms in a single month.
Forces across the country arrested 1,000 suspects during the operation to smash gangs. Twenty guns were also taken off the streets.
In Operation Mille, the largest of its kind, 200,000 cannabis plants were seized.
The guns and more than 40 other weapons such as crossbows and knives were confiscated. Around 11,000 officers were involved in the crackdown, involving every police force in England, Wales and Scotland.
The officers also seized £650,000 in cash from the criminal groups.
Gangs are also believed to have links to money-laundering, cocaine-trafficking and serious violence.
Police say large-scale industrial units and empty residential homes are used for cannabis farms.
Officers say the buildings can become dangerous as a result of farming, tampering with electricity supplies, fumes and water damage.
Steve Jupp, the National Police Chiefs’ Council lead for Serious and Organised Crime, said: “Organised networks involved in cannabis production are also directly linked to an array of other criminality.”
He said the linked crimes included Class A drug importation, slavery and “wider violence and exploitation”. He added: “Cannabis-related crime is often thought to be ‘low level’. However, there are patterns around the exploitation and violence crime groups use to protect their enterprises.
“We also frequently find that cannabis production is just one aspect of their criminal operations and that they are complicit in wider offending, which blights our communities.”
