The report by the International Labour Organisation finds global profits from involuntary workers an estimated 21 million of them have more than tripled over the past decade from its estimate of at least USD 44 billion in 2005.
ILO Director Guy Ryder said his agency's report today calls attention to the need "to eradicate this fundamentally evil, but hugely profitable practise as soon as possible."
Two-thirds of the profits come from sexual exploitation, it says, and one third is the result of "forced economic exploitation" that includes domestic and agricultural workers.
"We need to strengthen social protection floors to prevent households from sliding into the poverty that pushes people into forced labour," he said.
"We need to improve levels of education and literacy so that household decision-makers can understand their own vulnerability to forced labour and know their rights as workers."
It says 55 per cent of the victims are women and girls, primarily in commercial sexual exploitation and domestic work, while men and boys were primarily in forced economic exploitation in agriculture, construction and mining.