Birmingham police have been examining a disused industrial unit which was uncovered as a cannabis factory in Hockley this week.
Police were alerted to the ‘large-scale set-up’ by electricity workers, who had entered the property on a warrant at around 10.45am on Tuesday.
As they entered the unit, they heard voices, and once inside, the engineers discovered the building was being used to grow cannabis.
Those inside the property are believed to have fled from the rear of the building.
When officers arrived they found four rooms crammed with approximately 900 plants and a sophisticated hydroponics system.
Sergeant David Strong, from Birmingham Central police station, said: “This was a sophisticated and large-scale set-up containing 900 plants.
“It would appear that those behind the operation ran-off when disturbed by electricity workers. That was when we were alerted.”
The unit has now been cleared, the plants destroyed and evidence recovered.
Anyone with information on those dealing or growing drugs in their neighbourhood are asked to contact their local police station or call Crimestoppers anonymously on 0800 555 111.