A man was locked inside a giant cannabis factory for two months with just bags of rice to eat before being discovered during a police raid.
Quang Van Ho, from Vietnam, had been driven from London to northern Lincolnshire in the dead of night with the promise of a job.
But he was then locked inside a huge industrial unit on the Foxhills Industrial Estate in Scunthorpe and the doors were screwed down to stop him escaping.
Ho, 48, was left with two other men, aged 30 and 46, with just enough food, mainly rice, and liquids to survive and under orders to cultivate the huge cannabis farm hidden inside.
The shocking case emerged after a hearing at Grimsby Crown Court following the raid on July 28 which uncovered the £4m cannabis factory, thought to be the largest found in northern Lincolnshire.
Humberside Police found 15,000 cannabis plants at the warehouse which took almost a week to remove, GrimsbyLive reports.
Under industrial-sized heat lamps, powered by electricity re-routed from an underground mains cable, huge crops of cannabis were planted, grown, harvested and dried before being divided into shipments.
A fleet of four former Tesco home delivery vans was even used to distribute the drugs to and from the factory which helped supply a vast network of cannabis dealers across not just the town but Grimsby, Doncaster and large parts of Lincolnshire.
It is thought Ho, who had been ‘recruited’ on the streets of London, didn't even know he was in Scunthorpe.
The three men were arrested and charged with producing cannabis between June 1 and July 30.
But on Thursday they were cleared after the case against them collapsed because they were victims of modern-day slavery or people trafficking. Ho had spent six months on remand before the hearing.
Speaking after the hearing, solicitor advocate Richard Hackfath, who represented Ho, said: "He came into this country on his own passport on a visitor's visa but ended up being detained in an immigration detention centre.
"When he was released from there, he had got no means of support so somebody in London offered him a job and that's how he was brought to Scunthorpe in the middle of the night and was locked in.
"He was never paid and, if people refuse to work, they beat them. He was there inside the premises for two months."
Mr Hackfath said Ho was given just enough food and liquids to survive.
"There was a bag of rice and things they found in there," he said. "It was very rudimentary but just enough to keep him going.
"The other two were in there in exactly the same way but they came into the country in the back of a lorry. They said they had been smuggled in.
"They were locked in as well. It was placed into lockdown and was screwed down shut."
The other two men were found to be the victims of trafficking but the police did not provide the requested information to the Home Office about Ho.
"The Home Office had emailed and telephoned Humberside Police but had not had a reply," said Mr Hackfath.
"If the police had told the Home Office what they knew, it was likely that they would have dropped the case against Ho some time ago.
"That's why they have now dropped it."
At the hearing on Thursday, prosecutor Ben Thomas told Grimsby Crown Court that Ho was due to face trial as he had initially not been found to be a victim of trafficking.
However, Mr Thomas said there were no problems with the credibility of his account of how he came to be on the premises.
"It's not safe to proceed in respect of him," said Mr Thomas and a verdict of not guilty was entered.
It is understood Ho will have been released from Grimsby Crown Court with a travel warrant that would entitle him to buy a rail ticket to a destination in the country of his choice.
As his passport and visa remain valid, he is not subject to any deportation requirements.
Mr Thomas said the 15,000 cannabis plants found in the raid were estimated to have a street value of between £2.5m and £4m.
The factory was uncovered following police inquiries and information from members of the public.
Humberside Police Detective Inspector John Cram said at the time: "This is a hugely significant find.
"It is a very professional set-up which we believe to have been ongoing and operating for a period of months.
"It is certainly the biggest drugs operation in which I have been involved in this area in 30 years of working with Humberside Police. I have never seen a factory this big."
Humberside Police are understood to be continuing their investigation into the find to trace the suspected ringleaders behind the factory.
It is thought the factory was part of a County Lines organisation and the seizure had an immediate impact on cannabis supply across northern Lincolnshire.