A huge cannabis factory capable of producing more than one million pounds of the drug was discovered in an old school building in Lumb Lane, Bradford Crown Court heard on Friday.

Police busted the industrial-scale grow on May 4 disturbing the three gardeners who fled the scene.

A police officer waiting on nearby Carlisle Road, Manningham, chased and apprehended Jetnor Cuka, an Albania national who was in the UK illegally.

He was given a suspended sentence of imprisonment after Judge Neil Davey QC heard how he had been fooled by traffickers who promised him work in the construction industry.

He pleaded guilty to production of cannabis and wept on a video link to HMP Leeds as his barrister, Michael Blakey, explained that he had wanted to earn an honest living to send money back to his elderly and ill parents in Albania.

Prosecutor Mehran Nassiri said that part of the ground floor at the old school building had been converted to living accommodation, with three beds and a kitchen area.

There were a total of 1,310 cannabis plants on the premises comprising a crop of large plants and a smaller follow-on crop in the attic.

The 696 mature plants had a potential street value of £626,000, while the follow-on crop was worth more than £500,000.

Cuka, 48, told the police he had been living at the address for two months and had received no pay.

Mr Blakey said he had moved from Albania to Greece to work to support his elderly parents and was smuggled into the UK in December.

The gang told him he owed £22,000 for the trip and had to work at the cannabis factory to pay it off.

Mr Blakey said the living area at the school was very poor and Cuka’s plight was as close as it gets to modern slavery.

He was relieved when he was arrested and his ordeal was over.

Judge Davey said Cuka had been fooled and cheated by the traffickers.

“At bottom, I have no doubt that you are a decent, hard-working man,” he said.

“I have no doubt that living and working as you did was the last thing you wanted to do.”

Cuka had no previous convictions and had led a blameless life before then.

He was jailed for 16 months, suspended for 12 months.

It was a stand-alone sentence with no ancillary orders but Judge Davey told Cuka it was up to the Home Office what would happen to him.

In recent months, concerns have been raised about the number of cannabis farms being discovered in the Bradford district.

In July, cannabis farms with crops worth over £120,000 combined were found in neighbouring Great Horton homes.

At that point, Councillor Joanne Dodds said: "What frightens me is the danger of a fire or explosion from one of these, it is quite worrying.

"It is good news that they have got those drugs off the street and that it is intelligence from the community. Our message to them is always if you see something suspicious or not right always report it.

"Praise must go to the police too for spotting that second house."