Slavery in Europe: How big a problem is it?

British authorities recently rescued 24 men that they said were kept as slaves – some for as long as 15 years. The men, from England and parts of Eastern Europe, are "all believed to be victims of slavery," police said.

So, how big a problem is slavery in Europe? CNN's Max Foster talks to Anti-Slavery International's Aidan McQuade about the fight against modern-day slavery there and around the world.

FOSTER: We keep hearing how shocked people are that it's happening in their country, and it's often in the Western hemisphere that we hear that shock. But should we be shocked that it's going on?

MCQUADE: Yes. It is human beings doing this to other human beings and ... there's something like at least 12 million people enslaved in the world today. It's just an appalling, appalling carnage upon people's lives and hopes.

FOSTER: And in terms of the prevalence, are we right to say it's more or less prevalent in Western Europe, for example, than parts of Asia, where we've had lots of really horrific reporting?

MCQUADE: I think unquestionably in terms of absolute numbers, we're talking about South Asia being the largest numbers of people in the world.

But if you look at the International Labor Organization analysis of the problem, slavery in Europe and in North America - while it's smaller numbers, it's the high-value slavery. It's the thing that was making millions of dollars for people who are trafficking other human beings.

FOSTER: Because it's all about money, at the end of the day, isn't it? And all of the money's in Western Europe and the U.S., for example? The rich economies.

MCQUADE: Yes. And there's a basic rule in all business which is, if you can reduce costs, you will increase profits. And so there is a compulsion upon people-running - particular in the black and gray economies in this part of the world, to reduce their costs as much as they can by using slavery, for example.

FOSTER: Well, we did ask Britain's home office to join us on the issue. They declined, but they sent out this statement signed by the UK's immigration minister Damon Green.

It reads, "The government is tackling human trafficking and building on our strong record in supporting victims, fighting traffickers, and stopping this horrible trade from happening.

"We have recently published a national human trafficking strategy. We will be adopting the EU directive on trafficking, and we are creating the National Crime Agency to further improve our response to this brutal crime."

The statement goes on to say, "These measures, along with improved victim care arrangements will ensure that all victims, adults and children, receive care tailored to their specific needs." It implies that they haven't had that support in the past.

MCQUADE: I think Britain's record in terms of tackling slavery in the world is OK. It's not the greatest, but it's OK. But I think this current government has demonstrated both that they're ill-informed about the problem and broadly disinterested in relation to resolving it.

There's a number of measures which they are currently discussing. For example, removing the right for domestic workers to change employers. This is something which, if the government introduces this, will de facto legalize slavery again for domestic workers in this country. And again, they're not engaging with civil society, the big society about these issues.

The forced labor amendment, which was brought in in 2010, was brought in by Lord Bach, who was the minister of justice at the time. He was not initially persuaded to bring this in, but he listened to civil society's views on this.

FOSTER: Yes. And the politics in each nation does come into this. Often, a lot of it, when we talk about the Freedom Project, back to my initial point, people are often shocked that it's happening in their country.

But do you sometimes find the cases are worse in very developed societies because it's been hidden and people aren't assuming it's going to happen down the road, so it doesn't get noticed as easily?

MCQUADE: I think that's a strong point, yes. Because we believe this comforting myth that slavery's a thing of the past –

FOSTER: It wouldn't happen in our society.

MCQUADE: - so it shocks us more when it does happen. But if you look at the level of violence which is associated with slavery in Afghanistan or in Cote d'Ivoire, it's comparable to the sort of instances that we see here.

FOSTER: And we've got the Olympics, of course, coming up in the UK next year, and people are talking a lot about concerns about human trafficking in relation to that. Is that a genuine concern?

MCQUADE: Absolutely. I mean, there's two aspects to this. For one, we know that most people trafficked to the UK enter the country illegally, so with a lot more visitors coming to London, there's a lot more opportunities for that to happen.

But the second thing as well: you're talking about a lot of manufacture of Olympic goods stretching right across the globe. How sure are we that those supply chains are themselves free from forced labor?

And this is a question which I think is very reasonable to ask the companies which have got Olympic contracts to make public.