FAR East crime gangs are to blame for an epidemic of cannabis production in the region, The Northern Echo can reveal today.

More than 100 cannabis factories have been discovered in the North-East and North Yorkshire in the past year.

Many of the farms were run by organised crime gangs originating from Vietnam.

Experts say the gangs have links to people-trafficking and use illegal immigrants - including children - to tend the plants.

In Cleveland alone, police have closed down 21 farms so far this year - compared with only 15 during the previous four years.

The latest farm was discovered last week at the Golden City Chinese takeaway, in Norton Road, Stockton. About 300 cannabis plants with an estimated value of £200,000 were found.

Inspector Mel Ashley, senior investigating officer with Operation Basar, a force-wide crackdown on illegal drug production, said: "In the past 12 months, we've seen a massive increase in cannabis factories.

"The groups setting themselves up in Middlesbrough, Cleveland and other parts of the North-East are organised crime groups who are using cannabis production as a commodity, because of its high profitability - with what they deem as a low risk.

"They are able to take a large amount of profit for a minimum investment and will set up multiple premises in the area."

Earlier this month, five Vietnamese nationals were jailed for a total of 21 years after police found more than £300,000 worth of cannabis in seven houses across Stockton and Middlesbrough.

The previous week, police found 2,500 skunk cannabis plants - worth £500,000 - when they raided the old MAS Agraa Palace Indian restaurant, in Lynn Street, Hartlepool.

In North Yorkshire, 55 cannabis farms, ranging from small-scale operations to large factory sites, have been found in the past 12 months - 20 more than in the previous year.

Detective Sergeant Steve Smith said the farms were often staffed by illegal immigrants who had been brought to the UK with the promise of a better life, but were then forced to work to pay off debts to their traffickers.

Speaking about a raid at a cannabis farm in East Harlsey, near Northallerton, last November, he said: "The people we found had come through London.

"They were illegal immigrants. How they came into the country I don't know.

"Undoubtedly they would all have been exploited."

Det Sgt Smith believes gangs were setting up shop in North Yorkshire because of the abundance of remote locations.

"If someone is a bit smart and looks at a map of Britain, they will see that if you want an isolated farm barn away from prying eyes, this countryside is ideal," he said.

Northumbria Police recently seized about 2,000 cannabis plants - with a potential yield of about £2m - after a series of raids in Newcastle and Whitley Bay.

Detective Inspector Barry Worthen, the force drugs co-ordinator, said: "Sophisticated lighting and growing equipment are often found at these premises and it appears there are various organised crime groups - a trend which is being reflected regionally and nationally.

"As well as being illegal, this cultivation is dangerous.

"Bypassing the electricity needed to run the factories risks fire and electrocution, and they have already caused several devastating fires in other parts of the UK."

Today, 13 people, including 11 Vietnamese, are due to be sentenced at Teesside Crown Court following the discovery of four cannabis factories in County Durham.

Two of the defendants were only 17 when police raided the homes in Ushaw Moor, Sacriston and Bowburn, as well as a converted barn in Lanchester.

Information charity Drug-Scope said children as young as 14 have been found working as gardeners in cannabis farms.

Martin Barnes, the charity's chief executive, said: "Some have considered large-scale cannabis cultivation as an almost victimless crime, but the reality is that vulnerable young people are being exploited.

"Unfortunately, they find themselves victims twice over - both at the hands of the criminal gangs who brought them to this country, forcing them to work in cramped, dangerous conditions to fuel the illegal drug trade, and again when they find themselves treated as criminals by the UK authorities."

The charity said that, ten years ago, 11 per cent of cannabis sold in the UK was grown here, but this has now passed 60 per cent.

Research by DrugScope found that farms were initially restricted to the Greater London area.

But in the past 18 months, Vietnamese-run cannabis farms have been found in Wales, Birmingham, East Anglia, as well as the North-East and North Yorkshire.