RURAL North Yorkshire could be hiding hundreds of people in forced labour and modern slavery, according to a report.
The Forced Labour in the UK report was compiled by leading academics from the universities of Bristol, Dundee, Durham and Liverpool and published in June this year with the support of the Joseph Rowntree Foundation.
It says that people are being trafficked into the UK for sexual exploitation, but the number of people brought to the country for labour exploitation is set to eclipse that, and victims are often too scared or have too poor a grasp of English to find help.
Now author Gary Craig - a professor of social justice at the University of Durham - has spoken about concerns that front line workers do not know how to spot forced labour, or what to do if they find it.
Prof Craig told the Yorkshire Post newspaper that local "first responders" - from councils, the police, and charities - need better training and legal knowledge so they can tackle trafficking and modern slavery.
In the same report, North Yorkshire Police's Detective Superintendent Steve Smith said the the hidden "behind closed doors" nature of crime makes it harder to tackle.
The force has found men from both Vietnam and China working on isolated cannabis farms in the county, he said, raising concerns that they had been trafficked into the UK.
North Yorkshire's chief constable Dave Jones has is also reported to have said they will prosecute traffickers and the criminals behind forced labour for other offences in a bid to get them off the streets when difficult prosecutions for human trafficking itself are not possible.