Historically, the international understanding of exploitation in human trafficking law was restricted to instances of sexual exploitation, or the white slave trade. In 2000, the transnational crime of human trafficking was defined in one of three Additional Protocols to the United Nations Convention against Transnational Organized Crime. The entry into force of the Protocol to Prevent, Suppress and Punish Trafficking in Persons Especially Women and Children, supplementing the United Nations Convention against Transnational Organized Crime, 2000 (hereinafter: “the Palermo Protocol”) is considered as a ‘watershed in galvanising the global movement against trafficking’ as it not only addresses gaps in existing legal frameworks but also includes a ‘universally accepted’ definition in Article 3(a):

The definition consists of three constituent elements that must all be present for a situation to constitute trafficking in persons under international law: (i) an action; (ii) a means by which that action is achieved (except where the victim is a child; it is not necessary to prove that one of the acts was accomplished through the use of any of the listed means); and (iii) a purpose of exploitation. Whilst it is acknowledged that exploitation is dol specialis requiring evidence of an action and means for the ‘purpose of exploitation’, a United Nations Office on Drugs and Crime (UNODC) Issue Paper on the international definition of human trafficking notes that in practice, the existence of exploitative situations trigger investigations and constitute the ‘most compelling evidence of intention to exploit.’