Thermal images taken of Harrow to find beds in sheds have helped police find five cannabis farms.
Last week police raided one of the cannabis factories after they were discovered in the imaged taken by the remote controlled plane earlier this year.
Thermal imaging cameras were able to find cannabis factories which led police to raiding one of the homes in Harrow.
They found dozens of dozens of plants being cultivated in an upstairs bedroom and two people were arrested.
Leader of the council Susan Hall said: “The main purpose of the thermal image flight was to give us a scale of the issue with beds in sheds developments. But an unexpected benefit has been to expose these secret suburban cannabis factories.
“This isn’t some victimless crime. This drug is clearly being cultivated on a commercial scale for sale either locally or in London.
The people involved may be the foot soldiers of the enterprise, but they are at the base of an enterprise that is pumping drugs onto our streets.
“I think it is a great result for the people of Harrow that the thermal camera has caught the cannabis growers at it.”
Before the council commission flight planning officers estimated there were 75 cases of unauthorised 'beds in sheds' in Harrow.
Now there is a list of 319 potential cases identified in the evening flight, during which a thermal imaging camera was used to take aerial shots of the borough.