LAST week we reported that houses converted into cannabis factories are becoming an increasing concern for police in Herts. Twenty have been uncovered in the last three months. One of them was in Gonville Crescent, Stevenage. Now a man who lives next door

LAST week we reported that houses converted into cannabis factories are becoming an increasing concern for police in Herts.

Twenty have been uncovered in the last three months.

One of them was in Gonville Crescent, Stevenage.

Now a man who lives next door has revealed how he and other neighbours played a key role in identifying the factory where more than £54,000 worth of cannabis plants were discovered growing.

Richard Cory said: "I knew more or less within two weeks what was going on in there. They had put up curtains, shut all the windows and the curtains were never opened during the day, even in the very hot weather.

"The neighbour on the other side of the house said the one thing she noticed was that one of her walls was very hot and her boy couldn't sleep in his bedroom because it was so hot.

"We have a Herts area detective and I told him about it around three weeks after they moved in and he got in touch with the drug squad.

"They wanted the car registration numbers so we gave them that. I also gave them all the times they were at the house."

Police are appealing for help in detecting more converted cannabis houses.

There are a few tell tale signs that could indicate a factory is being set up or is already in operation. These are:

# The curtains are constantly closed

# There is a lot of noise when someone moves into a property but afterwards no one seems to be living there

# There is a strange smell

# Paper is put up inside the windows

# There is excess heat

# There is condensation on the windows or even on the brickwork of the house

Det Chief Insp Jon Chapman heads Operation Miss, a countywide police team looking into the organised crime chain which operates behind these factories.

He said: "Many of these things in isolation may not raise people's suspicions. However, if a few of these things seem to be happening then we'd like to hear from you. We can easily eliminate a legitimate house from our enquiries."

Hertfordshire Constabulary is willing to pay up to £5,000 for information that leads to the arrest and conviction of people responsible for organising this criminal activity.

Anyone with information that they think could relate to a cannabis factory is asked to contact police on 0845 33 00 222. Alternatively, ring Crimestoppers on 0800 555 111.