POLICE raided a huge cannabis factory in Clayton-le-Moors, recovering drugs with a street value of up to £30,000.
Officers swooped on the former shop premises on the corner of Whalley Road and Duke Street in a dramatic early-morning raid, following months of surveillance.
More than 800 cannabis plants in various stages of growth were discovered in the building, where an artificial "tropical" environment had been created to speed up growth.
Plants were found in the basement and three upstairs rooms of the factory.
The building was once home to contractors Colin Bibby Ltd, but officers said that the premises had been empty for many years and Mr Bibby now had nothing to do with the building.
The former shop had been converted with air conditioning and £10,000-worth of lighting, and a fuse box had been installed so that the equipment did not overload the mains supply.
PC Jason Manning, community beat manager for Clayton-le-Moors, said: "This raid came as a result of information supplied to Crimestoppers.
"We have kept observations on the property for the last few months.
"There were about 800 cannabis plants in different stages of cultivation up to 10 or 12 weeks of age.
"In my 14 years as a police officer this is one of the most professional set-ups I have seen. It's phenomenal.
"The equipment that has been used is of a very high standard. The lighting is worth about £10,000 and there are generators and heating to create a tropical climate, which is what is needed to grow the plants. They need a lot of time and cultivation to get like this."
A man was arrested in connection with the incident and has been released pending further inquiries.