A new report estimates nearly 46 million people around the world are trapped in slavery.
The Global Slavery Index found India has the most slaves, with around 18 million people in all. However, North Korea has the highest incidence of modern slavery at 4.37% of the population.
The Walk Free Foundation's study found every corner of the globe is affected. The figures are also ten million higher than the last register two years ago.
The organisation says people are being held as prostitutes, domestic servants or forced to work in factories or farms.
Although Europe is shown to have the lowest regional prevalence of modern slavery in the world, the researchers indicate that the continent "remains a destination, and to a lesser extent, a source region for the exploitation of men, women and children in forced labour and commercial sexual exploitation".
Current estimates suggest there are around 1,240,000 people enslaved in Europe.
EU citizens account for 65% of identified trafficked victims within Europe, mostly originating from Eastern Europe. Other victims are predominantly from Nigeria, China and Brazil, the report suggests.
There is a warning that the profile of victims may change over time as a result of the ongoing migrant and refugee crisis.
It is also said that forced marriage has become an 'emerging concern' within Europe, in countries including Spain, Germany and the UK.
Andrew Forrest, Chairman and Founder of the Walk Free Foundation, said: “We call on governments of the top 10 economies of the world to enact laws [...] with a budget and capability to ensure organisations are held to account for modern slavery in their supply chains, and to empower independent oversight.
“I believe in the critical role of leaders in government, business and civil society. Through our responsible use of power, strength of conviction, determination and collective will, we all can lead the world to end slavery," he added.