A Vietnamese refugee who helped set up a sophisticated 'cannabis farm'' at a rented house in Bradford has been jailed for a year.

Chien Chu, 29, was paid pocket money of £50-a-week to look after the hundreds of plants being grown at the semi-detached house in Kingsdale Avenue, Bolton, but a judge has warned the money men behind the increasingly common activity that they would face much longer prison sentences.

'Those who establish operations such as this, who provide the capital to pay the rent on such properties and purchase the expensive equipment that is necessary, must stand warned that they will receive very considerable periods in prison,'' said Judge Christopher Prince.

Bradford Crown Court heard today how £5,500 in cash was handed over to rent the house for a year, but when it was raided by the Bradford Drugs Team in May this year they found mature cannabis plants and seedlings being grown using a hydroponic system and lighting.

Prosecutor Bashir Ahmed said silver reflective sheeting had been used to line the walls of various rooms in the house and a sophisticated ventilation system had also been fitted.

'When the officers forcibly entered the premises they discovered 140 cannabis plants growing in two of the downstairs rooms,'' said Mr Ahmed.

'The walls had been lined with silver reflective sheeting. There was high-intensity lighting suspended from the ceiling and a sophisticated ventilation system.'' Officers found more than 200 seedlings growing in the hallway and two upstairs bedrooms had also been equipped for growing the Class C drug.

A back bedroom contained a large pile of drying compost ready for use on the seedlings.

Chu was arrested at the house and he later told police that he had been living there for six months.

He admitted feeding, watering and harvesting plants as well as helping to install the reflective sheeting, lighting and ventilation.

In addition to receiving £200-a-month he also got food and accommodation at the house.

Chu, who had £177 of his wages' on him when he was arrested, pleaded guilty to charges of producing cannabis and possessing criminal property, namely the cash.

His barrister Giles Bridge explained how his client had come to the United Kingdom in 2003 and had lived in London until moving to Bradford last year.

The court heard that Chu was an 'overstayer'' and Mr Bridge said he feared returning to Vietnam because he had been involved in activities with opposition groups in that country.

Mr Bridge said cases involving Vietnamese refugees and overstayers who are used by others to cultivate crops are becoming increasingly common.

Jailing Chu, Judge Prince said: 'This was an on-going operation that would have increased in output had the police not searched these premises and arrested you.

'Those others who recruited you paid £2,700 in cash for the first six months rental on the property and £2,800 in cash in advance for the second six months.

'That payment of £5,500 demonstrates the sort of profits that it was felt could be gained from this operation.

'You were being paid £200-a-month plus your accommodation and food for your part and it seems that you were recruited because of your particularly vulnerable circumstances in this country.'' Judge Prince said although Chu's role was a lesser one it was nonetheless an important one.

'It is conceded by the defence that it is increasingly common to find cannabis farms such as this. Persons in your position must be deterred from agreeing to help by the imposition of prison sentences.'' Judge Prince decided not to make any recommendation for Chu's deportation after his sentence saying that others were in a better position than him to take a full account of his circumstances.