Officers discoverd approximately 3,000 plants inside the building on an industrial estate in Gilmorton Road, Lutterworth.
Police believe the plants could have yielded cannabis worth approximately £4 million a year if the operation had not been stopped.
The plants were growing in a number of rooms inside the building, which was kitted out with a complex cultivation and ventilation system.
Three men, aged 24, 33 and 46, have been arrested and remained in police custody this afternoon.
Sgt Ed Des-Chanelle, of Leicestershire Police county local intelligence unit, said: “This is potentially one of the largest finds of cannabis in Leicestershire.
“Leicestershire Police along with other agencies will continue to crack down on the misuse of drugs and rid the streets of these harmful substances.
“Today’s successful result has stopped an estimated £4million of cannabis hitting the streets of Leicester, Leicestershire and Rutland and has stopped £4million lining the pockets of organised criminals.”
Source www.leicestermercury.co.uk
