Nearly 60 percent of countries have been listed in a new global index as being at high risk of using slave labour in their supply chains.
Risk analytics company Verisk Maplecroft found 115 out of 198 nations to be at high or extreme risk of using slaves.
Lead analyst Alex Channer said few countries were immune to modern slavery.
Modern slavery has become a catch-all term to describe human trafficking, forced labour, debt bondage, sex trafficking, forced marriage and other slave-like exploitation.
North Korea was ranked as having the worst record of slave labour, followed by South Sudan, Sudan and Democratic Republic of Congo.