Another Hungarian, held with Peter, proved bolder. He got away and though tracked down and returned to the flat in Huddersfield by the Roma network, he fought and shouted before being locked in the cellar. Neighbours rang the police. The Roma were arrested and Peter was set free. He has agreed to give evidence against them and is now awaiting the trial. "But what shall I do then? I have nothing to go back to in Hungary. And I am afraid. If they catch me, they will cut my throat." 

Though it has historical precedents in the white slave trade of the 19th century, it was only in the 1990s, after the surge in economic growth across the Philippines, Indonesia and Malaysia began to evaporate, that cross-border trafficking of jobless and desperate women really began. As Nick Davies rightly noted, there are no more reliable figures for trafficking for sexual exploitation than for any other forms of trafficking. However, the ILO have tentatively suggested that as many as 700,000 women and girls may be illegally and secretly taken across international borders every year, feeding an industry with profits put at between $12 billion and $17 billion per annum. Often sold on from owner to owner in a long cycle of abuse, women are said to make excellent merchandise: they can be duped and terrorised into submission and made dependent on drugs and alcohol, while the profits are vast and the chances of being caught minimal. And, like trafficked people everywhere, they can be forced to pay back the costs of enslaving them, in endlessly repeated "debts". One CIA report estimated that each trafficked woman may earn her recruiters and handlers $250,000.

But the issue of trafficking and prostitution has its own particular difficulties. As the recent debate in the UK makes clear, campaigns against traffickers have been dominated by activists from two opposing camps: those who see all prostitution as a violation of human rights, and those who differentiate between voluntary and forced prostitution. For them, sex work can be a legitimate choice. It is the idea of what exactly constitutes coercion that is in question: whether a woman ever, in fact, actually "consents" to prostitution, or whether she is not always forced into it — by poverty, desperate need or violence. For a while, the subject of trafficked women became a target of intense feminist lobbying in the US, with Christian evangelists and some feminists uniting in their view of a world full of evil inflicted by men on women, using sex as a form of abuse. 

The 2000 Palermo Protocol to the UN Convention against Transnational Crime is the international legal document that addresses all forms of trafficking in people. According to this protocol, trafficking is said to take place when a person is moved, by means of deceit or coercion, into a state of exploitation, whether of forced labour, slavery, servitude, sexual exploitation or removal of organs. Mira, Natasha and Peter all come under its rubric. With children under 18, it is enough that they be recruited and exploited. 

Initially debated with transnational crime in mind, the protocol focuses on encouraging states to adopt laws against trafficking. Law enforcement is obligatory for all signatories. The protocol — ratified to date by 117 states and signed by 110 — has been followed by a wide range of initiatives by the EU, the Council of Europe, Interpol, various UN bodies, OSCE and an immense number of NGOs.