The International Labour Organization (ILO), human rights group Walk Free Foundation, and International Organization for Migration said 40.3 million people were victims of modern slavery in 2016 – but added this was a conservative estimate.

They estimated 24.9 million people were trapped working in factories, on construction sites, farms and fishing boats, and as domestic or sex workers, while 15.4 million people were in marriages to which they had not consented.

Almost three out of every four slaves were women and girls and one in four was a child, with modern slavery most prevalent in Africa followed by Asia and Pacific, said the report.

The ILO also released a separate report showing 152 million children were victims of child labor, which amounted to nearly one in every 10 child worldwide, with almost half of those engaged in hazardous work.

Half of forced labourers were victims of debt bondage, who were made to work to repay a debt or other obligation, and nearly four million adults and one million children were victims of forced sexual exploitation.

“Forced labourers produced some of the food we eat and the clothes we wear, and they have cleaned the buildings in which many of us live or work,” the groups said in a report released on Tuesday, stressing the crime was prevalent in all nations.

The ILO also released a separate report showing 152 million children were victims of child labor, which amounted to nearly one in every 10 child worldwide, with almost half of those engaged in hazardous work.

The findings mark the first time the groups collaborated on an international estimate and prompted calls for stronger labor rights, improved governance of migrants, action to address root causes of debt bondage, and better victim identification.

Previously the groups had used different data, definitions and methodologies, said Houtan Homayounpour, a specialist on forced labor at the ILO, the United Nations’ labor agency.