The number of people identified as potential victims of human trafficking in Britain rose by 21 percent last year, as police and other professionals have got better at spotting signs of the hidden crime, the National Crime Agency (NCA) said on Wednesday.
A total of 3,309 people were identified, compared with 2,744 in 2013, the NCA said. About one in five of them were children.
In March, Britain passed a law to crack down on traffickers, clean up supply chains and introduce measures to protect people at risk of being enslaved - amid concerns not enough was being done to stop modern day slavery, a scourge affecting tens of millions of people worldwide.
Victims reported to the police were being forced to work in private houses and in hospitality, farming, manufacturing and construction industries - with traffickers using threats and violence to ensure compliance.
According to a 2003 U.N. protocol, trafficking is defined as the recruitment, transport or transfer of people through the use of force, coercion and fraud for the purpose of exploitation.
One of the problems to ending slavery in Britain, where an estimated 13,000 people are enslaved, was that many victims did not consider themselves to have been exploited, the NRC said.
"Human trafficking is an insidious and complex crime where much of the exploitation is hidden from view," Caroline Young, deputy director of the NCA's Organised Crime Command, said in a statement.
Levels of reporting have risen in the last two years at a similar rate, a sign that law enforcement and first responders are increasingly encountering and recognizing examples of trafficking in Britain, Young said.
"...the first step in being able to assist the victims and tackle the criminality", she added.
The victims came from 97 countries with Romania remaining the top country of origin for the fourth year in a row, followed by Albania, Britain, Slovakia and Poland.
The data also showed that, for the first time, there were more Romanian victims of labor exploitation than sex trafficking.
The NCA said the number of Britons identified as potential victims of human trafficking rose to 300, an increase of 55 percent, and that more British children were trafficked than any other nationality.
In some cases, traffickers used social media and smartphone messenger apps to recruit British victims, the report said. It also found that vulnerable boys and girls were being groomed by older men, who plied them with drugs or alcohol.