You can help smash the growing phenomenon of cannabis factories in Oxford neighbourhoods by being the eyes and ears of the police in your street.

Yet another sophisticated cannabis factory was uncovered yesterday - this time in Cricket Road, Cowley.

Police believe they have discovered a plot to run a network of drugs factories in quiet residential streets across the city.

Many of the drugs factories discovered by police have a lone 'gardener' inside to grow the cannabis and maintain a complex irrigation system and rewired electric circuits, which bypass the meter.

Police are also warning some of the homes are booby-trapped and the rewiring can be dangerous.

Yesterday's discovery of a cannabis factory inside a semi-detached, three-bedroom home is the 15th found in Oxford in the past year.

Police removed 160 cannabis plants with a street value in excess of £30,000.

Det Insp Cecilia Agger said: "Essentially what is happening appears to be a relatively new phenomenon, with a number of similarities and patterns with others found across the city.

"The majority are rented properties and there are similarities in the way equipment has been set up and how cannabis is looked after. A gardener regularly maintains what is in effect a cannabis factory."

Officers would not discuss tactics being used to find these factories, but said some recent discoveries were due to members of the public becoming suspicious and tipping off the police.

Ms Agger added: "We need their help to deal with these cannabis factories and they are a vital part of our investigations."

In yesterday's raid, police found four rooms filled with about 160 mature plants and evidence that a further 140 plants had been harvested.

A team from Southern Electric discovered the meter had been bypassed. There were 42 lamps which would have cost an estimated £35 a day to run.

No-one was inside the house.

Neighbour Robert Dean, 88, of Cricket Road, said: "It was a shock to find out. I wouldn't like to think there were people like that about growing drugs living next door. You don't want rubbish like that hanging around."

Anyone who suspects there is a cannabis factory in their street can read our checklist and contact police on 08458 505505 or anonymously to Crimestoppers on 0800 555 111.

SPOTTING THE SIGNS HOW to spot if next door is a cannabis factory: People are coming and going but not living there.

Curtains are closed at all hours and windows are never open.

Silver foil has been stuck in the windows acting as insulation.

Fertilizer is being carried into the house.

There is a smell of cannabis.

Neighbours living in terraced or semi detached homes may notice increased heat and cannabis smells in the loft.