There are at least 8.4 million child slaves in the world today, many of them held as forced labour.
Poverty-stricken men from the north of Brazil are often lured to remote camps where they are used as slave labour.
India has the world's largest number of slaves, among them an increasing number of women and girls sold into marriage.
Making the series
Far from ending with the abolition of slavery, the trade in human beings is thriving more than ever before.
This new series gives a voice to modern-day slaves, goes in search of the slave masters and asks why slavery persists.
From the experts
For the cost of a bridge or a light-railway system, 27 million people could be taken out of slavery once and for all.
'I do not want to consume their suffering with my morning cup of coffee.'
Some journeys start with 'boyfriends', others with organised gangs - most end up on the streets of Western cities.
Toos Heemskerk-Schep

About the series

Today, 27 million men, women and children are held, sold and trafficked as slaves throughout the world. In Slavery: A 21st Century Evil, Rageh Omaar embarks on a worldwide journey to uncover the truth about the flourishing 21st century slave trade. Episode by episode, his investigation will expose the brutal reality of modern slavery and unpick the reasons why this age-old evil persists.

When to watch

Slavery: A 21st Century Evil can be seen from Monday, October 10, at the following times GMT: Monday: 2230; Tuesday: 0930; Wednesday: 0330; Thursday: 1630.

About the episodes