The details were given in a research report prepared by the Walk Free Foundation, an initiative set up in 2012 by Australian billionaire mining magnate and philanthropist Andrew Forrest.
The researchers compiled information from 167 countries after conducting 42,000 interviews in 53 languages to determine the prevalence of the issue and government responses. The research said that there were 28 percent more slaves than estimated two years ago.
According to report, India had the highest number of people trapped in slavery at 18.35 million, while North Korea had the highest incidence (4.37 percent of the population). Modern slavery is used to define situations of exploitation that a person cannot leave because of threats, violence, coercion, abuse of power or deception.
"We call on governments of the top 10 economies of the world to enact laws, at least as strong as the UK Modern Slavery Act 2015, with a budget and capability to ensure organisations are held to account for modern slavery in their supply chains, and to empower independent oversight," Forrest said.
"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.
Talking in absolute numbers, Asian countries occupy the top five for people trapped in slavery. Behind India was China (3.39 million), Pakistan (2.13 million), Bangladesh (1.53 million) and Uzbekistan (1.23 million).