Baku. 29 November. REPORT.AZ/There could be between 10,000 and 13,000 victims of slavery in the UK, higher than previous figures, analysis for the Home Office suggests.
Modern slavery victims are said to include women forced into prostitution, "imprisoned" domestic staff and workers in fields, factories and fishing boats.
The figure for 2013 is the first time the government has made an official estimate of the scale of the problem.
The Home Office has launched a strategy to help tackle slavery, informs Report citing BBC.
It said the victims included people trafficked from more than 100 countries - the most prevalent being Albania, Nigeria, Vietnam and Romania - as well as British-born adults and children.
Data from the National Crime Agency's Human Trafficking Centre last year put the number of slavery victims in the UK at 2,744.
The assessment was collated from sources including police, the UK Border Force, charities and the Gangmasters Licensing Authority.
The Home Office said it used established statistical methodology and models from other public policy contexts to estimate a "dark figure" that may not have come to the NCA's attention.
It said the "tentative conclusions" of its analysis is that the number of victims is higher than thought.