CANNABIS seizures in Suffolk have seen around a fivefold increase over two years, with 7,000 plants being discovered during police raids in one 14-month period.

According to Suffolk Constabulary, 1,321 plants were seized during 21 raids where 10 or more plants were confiscated in the 2007/08 financial year.

However, between June 1 last year and August this year, there were 22 raids on cannabis factories, but this time they yielded more than 7,000 plants in total.

The figures show growing the Class B drug is a multi-million pound industry and often linked to organised crime gangs.

The majority of the premises used for cultivating the drug in Suffolk are rented properties in residential areas.

Rooms are crammed full of plants, upstairs and downstairs, and the premises are converted to accommodate special hydroponic equipment and lighting necessary to ensure the crop is maximised.

This kind of ‘factory’ is not the only type of property where cannabis has been found.

On at least three occasions over the past year, there have been hundreds of plants found at small holdings in central and west Suffolk.

A leading Suffolk drug rehabilitation expert said although cannabis was a comparatively safe drug when compared to cocaine or heroin, it still affects people’s health.

Chip Somers, chief executive of Focus 12 in Bury St Edmunds, said: “For those with a propensity for mental illness cannabis can be extremely counter-productive and lead to mental health problems.

”Cannabis is by far and away the most available drug in Suffolk. Over the last few years, more and more people have found out how to make it as that kind of information is more readily available. That spread of knowledge has obviously increased the spread of production.”

Detective Chief Inspector David Cutler, of Suffolk police, said: “There is a growth in what we are finding. The more we educate the communities and the wider public, the more information we get about what is going on as more of these premises get spotted.

“There is a huge amount of profit to be made. The big commercial factories we are talking about can have a turnover of more than �1million a year.

“These are organised and very professional set-ups. It’s almost like a battery farm for cannabis. It is a constant turnover for high-intensity farming.

“The vigilance of people living in the communities is important. People shouldn’t be apprehensive to contact us if they feel there is something wrong. There are easy steps we can take to look at these premises in a covert way.”

Det Ch Insp Cutler urged landlords and residents to look out for unusual signs, such as a lot of activity, and if the curtains are left permanently drawn or a neighbours notice a strong, pungent odour.