A CANNABIS factory unearthed by police in Bromyard had the potential of netting almost £4 million a year.

Worcester Crown Court heard that the two illegal immigrants cultivating nearly 2,200 plants there lived in ‘abject squalor’ as virtual prisoners.

Judge Toby Hooper QC, sentencing the two Vietnamese men, last week, said: "It was a massive operation capable of doing an enormous amount of harm in our communities.”

He told Hue Nguyen and Dieu Mai they had been "trafficked into this country, then exploited under cover for very little personal gain, in circumstances of pressure, coercion, exploitation and intimidation".

Nguyen, aged 48, and Mai, 44, who were living at the raided premises on Bromyard Business Park, Tenbury Road, admitted producing cannabis and were each jailed for two years.

The judge said they were now almost certain to be deported.

Paul Whitfield, prosecuting, told the court police armed with a search warrant found 2,180 cannabis at various stages of growth being cultivated in 12 growing rooms at the former industrial unit on February 18.

A sophisticated hydroponics system had been set up to maximise the yield and the plants had the potential to produce 103kg of skunk cannabis – with a street value of £3,942,000 – every year.

Mr Whitfield added that Nguyen and Mai lived in "spartan" accommodation with mattresses on the floors to manage, irrigate and breed the plants, while food and drink was dropped outside for them monthly and they were not allowed to go out.

Nguyen did not know who had brought him to Bromyard but he was grateful for the food and money he was given there.

Mai had been approached by someone in the street and given £120 to go to Bromyard to join Nguyen.

Mark Thompson, defending, said that Nguyen had been ‘coerced’ into tending the plants and, when he told his bosses that he was leaving after 20 days of working there alone to the "point of exhaustion", their response was that he would be found and beaten up.

Mai was then brought in to help Nguyen.

Both were desperate, with no permanent address in a strange land, and they "lit up like a beacon" when people in Birmingham asked them to come to earn some money.

“They were gardeners – tending to the crop,” said Mr Thompson.

“But they were living in abject squalor, locked in with food left outside – they were prisoners in a very real sense.”

Mr Thompson added that Nguyen,a father of three, left Vietnam in 2006 after floods hit his home region and he paid £1,000 to travel through Russia and Poland before ending up in the UK in 2010.

Mai came to the UK about four months ago hoping to earn money to send to his wife and children, living in poverty in Vietnam.