A new report suggests that human trafficking was the second most profitable criminal activity after drug trafficking worldwide last year.

According to a report funded by the Ricky Martin Foundation, which is a major donor to anti-child exploitation causes worldwide, the illicit trade in human beings brought in $9.6 billion in profits worldwide last year. The report, which was released at a November 14 conference on human trafficking in Puerto Rico, claims this represents a three-fold increase from 2009.

The finding clashes with figures used in two recent reports conducted by Global Financial Integrity and the UN Office on Drugs and Crime. These use data compiled by Patrick Belser of the International Labor Organization, who places the number far higher, at $31.6 billion annually. These two organizations both estimated that this figure makes human trafficking the third most profitable illicit activity, behind drug trafficking and counterfeiting.

While the Ricky Martin Foundation has not published the methodology behind their report, the discrepancies with other profit estimates for human trafficking are not surprising. This is linked to the difficulties associated with defining human trafficking, and differentiating it from other related activities such as migrant smuggling.