Modern slavery contributes to the production of at least 122 goods from 58 countries worldwide, according to the report by the Australian anti-slavery campaign group Walk Free. The International Labour Organization (ILO) estimates the illicit profits of forced labor to be $150 billion a year.
"From the Thai fisherman trawling fishmeal, to the Congolese boy mining diamonds, from the Uzbek child picking cotton, to the Indian girl stitching footballs, from the women who sew dresses, to the cocoa pod pickers, their forced labor is what we consume. Modern slavery is big business," Walk Free states in its report, claiming it has found evidence of slavery in all 167 countries it surveyed.
The 10 countries with the highest estimated prevalence of modern slavery as a proportion of population are Mauritania, Uzbekistan, Haiti, Qatar, India, Pakistan, the Democratic Republic of the Congo, Sudan, Syria and the Central African Republic.
For the second year running, India has turned out to be home to the greatest number of slaves, with over 14 million people in its population of 1.25 billion labeled as victims of slavery, spanning from prostitution to forced labor and making up nearly 40 percent of people in slavery worldwide.
The other nine countries with largest estimated numbers of people in modern slavery are China (3.2 million), Pakistan (2.1 million), Uzbekistan (1.2 million), Russia (1.05 million), Nigeria (834,200), the Democratic Republic of the Congo (762,900), Indonesia (714,100), Bangladesh (680,900) and Thailand (475,300). Taken together, these 10 countries account for 71 percent of the total estimated 35.8 million people living in modern slavery these days.
Nigeria and Ethiopia appear to be major source countries for migration overseas. Women and children from Nigeria are trafficked for sexual exploitation through organized crime rings to Europe.
"In Italy in particular, some Nigerian women are trapped in a cycle of debt bondage in the sex industry, with little hope of clearing €50-60,000 [$65-75,000] debts owed to their exploiters," the authors of the report say.
For Ethiopians, lucrative employment opportunities in the Middle East draw thousands to migrate for jobs in the construction and domestic work sectors. However, once in the destination countries, they are subjected to harsh working conditions instead.
The authors of the report assert that the strength of organized crime has aggravated the problem. People are lured into accepting tempting job offers overseas, which instead turn out to be sexual exploitation and forced labor.
Uzbekistan, a Central Asian nation whose economy mostly relies on production and export of cotton, has the highest prevalence of people enslaved in the region. Almost 4 percent of the Uzbek population (approximately 1,201,400 people) is subjected to slavery during the annual cotton harvest, the survey has showed.
Qatar, the small Gulf state known to engage significant numbers of foreign workers, has an estimated 1.4 percent of the population involved in modern slavery.
All countries, with the exception of North Korea, have domestic legislation which criminalizes some form of modern slavery. Among the countries with the weakest responses to modern slavery are Iran, Syria, Iraq, Eritrea (a country in the Horn of Africa), the Central African Republic, Libya, Equatorial Guinea, the Republic of the Congo and Uzbekistan.
The survey has showed that conflict had a huge impact on the spread of slavery.
"Statistical testing confirms the relevance of modern slavery to conflict situations as we have seen this year in Syria and the horrors perpetrated by the terrorist group Islamic State," it reported.
For the first time, governments were also rated on the adequacy of their response to slavery.
According to Walk Free, the Netherlands, Sweden, the US, Australia, Switzerland, Ireland, Norway, Britain, Georgia and Austria had the strongest responses to the problem.
Ireland and Iceland sit at 166 and 167 in the 2014 Index with the lowest prevalence of modern slavery.