It may be 200 years since the abolition of the slave trade in the UK, but it would be wrong to think people are no longer being brought into the country to work in appalling conditions against their will.
Operation Pentameter led to 84 trafficked women being rescued
Police investigating human trafficking and slavery across the UK have to admit they still do not know the full extent of the problem.
In 2000 the government set up Reflex, a taskforce aimed at co-ordinating the law enforcement response to people trafficking - funded by the Home Office at £20m a year.
Last year, Reflex funded Operation Pentameter, a Home Office initiative aimed at rescuing sex workers held against their will.
'Trapped and kidnapped'
The operation saw 84 trafficked women or girls rescued between January and July 2006, despite the fact police involved in it were only able to visit about 10% of the estimated total of sex establishments in the country.
As the operation came to a close, it was announced that the UK's first specialist centre to co-ordinate the police approach to combating people trafficking was to be set up.
The United Kingdom Human Trafficking Centre (UKHTC) opened in Yorkshire in the autumn of 2006 based in a secret location in Sheffield.
It combines research and intelligence teams and builds on the results of Operation Pentameter and the work done by police forces before and since.
A spokesman for the centre said: "Operation Pentameter wasn't the start, it was a concerted national campaign trying to get to grips with the extent of the problem, and we are doing ongoing work all the time.
"We know we've got a problem and we are trying to investigate it better.
"It's not a problem that's unique to the urban areas, it takes place in the suburbs and the countryside as well - wherever you've got a demand for sexual services.
"You've also got labour exploitation, people working in things like fish processing, some of whom have been trafficked, and people working as servants who have been exploited.
"It isn't just about illegal immigrants. We've got a lot of people who are EU citizens but are exploited by criminal gangs who have trapped them or kidnapped them.
The centre was opened in the autumn of 2006
"We also have internal human trafficking within the UK, people who are perhaps less well educated and come from a background of poverty who can be moved from town to town and exploited."
The team working at the centre consider raising the public's awareness of the issues of people trafficking, sex slavery and exploitation as a key part of their role.
They hope that by making people see the effects of the trade, they might prompt a change in opinion that sparks a fall in demand for prostitution.
The spokesman said: "Anything we can do to raise awareness of these issues is important.
"I would hope people would be worried at the extent of the problem and would be very much against it.
"Rather like William Wilberforce who got a group of people together to act against slavery, it's a case of creating an environment where it's not acceptable.
"Like the climate that's changing around mobile phones and driving or cigarette smoking, the shift in public opinion takes time.
"It's creating an environment where people think 'hang on, I can't do that because it impacts on individuals'.
"The people are severely traumatised and have to live with this for the rest of their lives."
He said the officers dealt with a girl from Lithuania who was brought to England thinking she was going to be selling ice cream in the summer.
"But she was sold in a coffee shop at Gatwick Airport and went on to be repeatedly raped, abused and beaten and used as a prostitute - and this was a 15-year-old girl," he said.
"We are investigating cases like this on a regular basis and it's good that we have got very robust laws - in the case of the Lithuanian girl two men got sentences of 21 years and 15 years, and others were arrested and jailed in Lithuania.
'Concerned or distressed'
"We will chase after these people, not only nationally but internationally.
"It poses problems when it's an international crime and brings challenges which aren't straightforward but we are getting used to it."
He said raising awareness of the devastating impacts of the trade could lead not only to a reduction in demand, but also improve the chances of people trafficking being stopped before it happens.
"Any form of transport you are on, there may be a trafficking victim with you.
"Wherever you are and wherever you are going, you might have a trafficking victim in your midst.
"She may look a little concerned or distressed or they may not even know until they are sold that they are being trafficked, but if people start to recognise the signs, they may think to tell someone in authority."