More than 12 million people, half of them children, are victims of forced labour across the globe, according to a new report by the International Labour Organisation (ILO).
In the first-ever estimates of the scale of the problem, the ILO said at least one-fifth of the 12 million were victims of illegal human trafficking – mainly for the sex industry.
The Geneva-based organisation called for urgent action to tackle the growing problem, which it estimated netted traffickers about US $32 billion each year.
"Forced labour is a major global problem, present in all regions and in all types of economies," Juan Somavia, ILO Director-General, said in the report. "In the industrialised world, forced labour is a growing challenge. The numbers may be far smaller than in the developing countries but the trends are disturbing."
The worst cases of forced labour were in Asia and the Pacific, the ILO said. In Africa alone there were 660,000 victims of forced labour – with traffickers making annual profits in the region of $159 million. Almost half of victims were trafficked for sex.
"The challenges of addressing forced labour are daunting," Somavia said. "Most forced labour today exists in the developing world, where victims come from the poorest economic and social groups. They are often without assets other than their labour."
The report called upon governments to crack down on the problem.
"Far too often, forced labour remains an invisible crime, largely hidden from view and prosecution," Somavia said. "Governments are sometimes reluctant to probe into and recognise its existence. Our messages to decision makers are straightforward - face up to forced labour. Tackle the root causes embedded in patterns of discrimination, deprivation and poverty.
"Victims themselves may be unwilling to come forward, fearing not only reprisals from their exploiters but perhaps also action against them by immigration and other law enforcement authorities," he added.
The ILO stressed the importance of clear legislation against forced labour, so that employers’ and workers’ organisations as well as the general public, would understand the issue.
The organisation also called for national programmes to end forced labour, and more resources for law-enforcement agencies. Such measures would enable governments to implement laws and policies and to identify, track down, prosecute and punish offenders.
Somavia said: "In all of these ways, we can make a real dent in forced labour and build a global alliance that ends this scourge once and for all."