A CANNABIS factory was uncovered by fire fighters yesterday after they attended a Blackburn town centre blaze.

Blackburn firefighters were called to an electrical fire in Byrom Street at the former two-storey AD Upholstery building at 10.55am. The fire was well alight on the ground floor.

But they discovered rows of eye -level heating equipment on the second floor of the brick building, instruction manuals on growing the class C drug and more than 600 kilos of compost.

Seed trays, digital thermometers, soil acidity monitors and manuals on cannabis species were found along with leaflets describing the 'high' from Choc Chunk, Kal-X, Stinky Pinky and Mr Bubble.

Windows on the second floor had also been bricked up and insulated. Police confirmed there were no plants or seedlings found on site.

Assistant divisional officer Paul Ashworth said: "The fire was popping and banging when we got there so we knew electricity was involved.

"When we ventilated it was clear they were refurbishing but we were horrified to see what for.

"Upstairs there were two rows of 11 heaters and all the extras for growing big quantities of cannabis. I have never come across anything like this before."

Sub Officer Beau Gaskin added: "There has clearly been a lot of money spent on getting the place ready for some kind of cannabis production farm."

Fire fighters stayed on scene for two hours. The ground floor was badly damaged by fire and the first floor was damaged by smoke.