Al Jazeera's Investigative Unit goes undercover to reveal the true scale of modern slavery in suburban Britain.
Reporter David Harrison and the investigative team expose the slave masters and the people smugglers and talk to victims about their ordeals.
Al Jazeera's investigative unit has revealed that large companies in Britain may be failing to tackle slavery along their supply chains.
The findings prompted a warning from Britain's anti-slavery commissioner that companies all over the United Kingdom could unwittingly be using modern-day slaves.
But Kevin Hyland, the UK's independent anti-slavery commissioner, said that new laws mean that ignorance is no longer an excuse.
Secret filming by Al Jazeera uncovered shocking conditions at a carwash in Kent, southeast England, used by dealerships for the auto giants, Volvo and Kia.
Workers living in squalid containers at the carwash in Canterbury say they are paid $50 for 12-hour shifts, suffer verbal and physical abuse, and have wages withheld for causing minor damage.
Parosha Chandran, a leading human rights lawyer, said Al Jazeera's evidence "appears to show all the hallmarks of modern slavery," adding that she has "grave fears that these workers are victims of human trafficking".
"What is absolutely necessary is for Volvo to investigate all parts of its supply chain in terms of labour," she adds. "Who is cleaning its cars?"
A new law introduced this month requires big firms to publicly and prominently report what they are doing to ensure there is no slavery in their operations and supply chains.
But our research found that 85 percent of the FTSE 100 and other leading companies do not address the Modern Slavery Act prominently, and nearly half make no mention of slavery at all on their websites.
Out of 20 other large companies surveyed, only two acknowledged the Act.
"Last year, there was a significant increase in the amount of people who are in forced labour," Hyland says. "We realise that a large percentage of these are in legitimate supply chains.
"The legitimate and the illegitimate economy become one in some ways because, actually, companies and people don't realise … that they are using … modern-day slaves in their supply chain."
"I'm absolutely sure that no chief executive officer, no director, no ethical British company wants to be paying money to criminals who are keeping people in modern-day slavery. But this [investigation] highlights how businesses in the United Kingdom could be unwittingly funding criminal activity," he says.
But Hyland emphasises that the new laws mean that companies pleading ignorance is no longer an option.
"We've got a Modern Slavery Act; we've got regulations saying we want transparency in supply chains. So people can't say they don't know anymore."