A SPECIAL police unit has been set up to tackle Vietnamese drug lords running cannabis farms in East Lancashire.

Police have smashed several large-scale cannabis factories across the region in the past two years, with the majority run by crime barons from the South East Asian country.

Now the dedicated team will look into catching the crime lords behind the farms, who are thought to be involved in other organised crimes.

Officers will also use the latest methods available to find the factories, including heat-detection devices which can be fitted to helicopter.

These are able to spot buildings producing unusually large amount of heat, which speeds up the growth of the plants.

Police said illegal immigrants were often brought to Britain to act as on-site ‘gardeners’ for the operations on behalf of the crime bosses.

These Vietnamese immigrants, often believing they are being rescued from a life in poverty, are shipped over by gangmasters who order them to work in factories or face deportation.

Above them are often co-ordinators, who organise equipment to grow the plants, and the financiers, who bring the drugs in.

Last week, a 34-year-old Vietnamese ‘gardener’ was convicted of cannabis cultivation for growing one of Blackburn’s biggest ever drugs farms in the Copy Nook area.

Hai Cheng was arrested by police after they raided the industrial unit and found a £340,000 operation in business premises in Gate Street.

Officers uncovered 1,700 plants in various rooms in the property and cannabis-growing instructions in Mandarin.

Cheng, of Coat Bridge Street, Manchester, denied producing cannabis but was convicted following a trial at Burnley Crown Court.

He will be sentenced next week.

Detective Inspector Claire Holbrook said: “These people are paying the debts of their illegal entry into the country.

"There have been instances where children have also been living within these dangerous situations.

"The sad thing is, in this case Mr Cheng was clearly not the mastermind behind the sophisticated set-up.

“However, his actions in tending such a large crop clearly could result in a flood of this sought-after drug swamping the local area, and the associated problems that cannabis causes in users.”

Last year it was estimated that Vietnamese crime bosses were making at least £2million a year from drugs factories in the area.

Mrs Holbrook said detectives now raid cannabis factories in East Lancashire “on a regular basis” and were getting tough on the “evil individuals” behind the operations.

She said officers from the unit were working with the authorities in Vietnam to trace criminal links back to the Asian countries in a bid to stamp out the problem.

The team, part of the Serious and Organised Crime Unit, based at police headquarters in Hutton, will also be liaising with counterparts from neighbouring forces, such as Greater Manchester and West Yorkshire.

The Copy Nook cannabis farm is merely the latest bumper find in East Lancashire - and increasing unassuming locations are being used.

Last month, police raided a detached house in leafy Royds Avenue, Accrington, and found a £150,000 cannabis factory with 400 plants. A Vietnamese man was arrested at the scene.

Four Vietnamese illegal immigrants who ran huge cannabis farms from a flat, a house in Nelson and landmark Burnley pub, The Duke of York, were also jailed last year for producing around 1,350 cannabis plants.