Our researchers are part of an extensive national and international scientific network dealing with this issue. They collaborate, for example, with researchers from Radboud University (Netherlands), the Violence and Justice Research Lab of Northeastern University in Boston (US), the Trafficking in Persons – Risk to Resilience Lab of the University of South Florida in Tampa/St. Petersburg (US), the University of Leeds (UK), and the University of Luxembourg. When it comes to the design, development and the results of the research projects, the researchers also look to practice, and involve parties in the Netherlands such as the Ministry of Justice and Security, the Public Prosecution Service, the police, support agencies and social organisations.

The research outcomes are shared through various channels including (open access) publications, conferences, expert meetings and workshops. The practical implications of our research are shared with parties involved in policy and practice. We do this, for example, through expert meetings and presentations, by sharing research summaries, publishing fact sheets or making animated videos.

Guest lectures at secondary schools

Various members of our research team offer guest lectures on human trafficking and related issues, aimed at secondary school pupils (primarily 4th to 6th year pre-university education (VWO)). These lectures consider, among other things, the (legal) definition of human trafficking, as well as some prevalent myths and our current knowledge on the issue. Not only do they aim to inform pupils about criminology as a research topic and a degree programme taught at Leiden University, but also to teach them about recognising exploitation – the vulnerabilities and risks involved – also in their own social context.  

These guest lectures can also be given in English.  

Information on these guest lectures is available here (in Dutch).

Within the bachelor's programme Criminology

Human trafficking is an issue that is high on the agenda of both the Dutch government and the EU. As such, it is frequently discussed in various courses in the BSc Criminology, including, but not limited to:  

• Inleiding Criminologie (Introduction to Criminology) 
• Inleiding Sociologie (Introduction to Sociology) 
• Daders (Offenders) 
• Slachtoffers (Victims) 
• Kwalitatieve Onderzoeksmethoden 1 & 2 (Qualitative Research Methods 1 & 2) 

For their bachelor’s thesis, students can also choose to conduct a literature review on a topic related to human trafficking and exploitation. 

Information on this degree (in Dutch) can be found here. 

Students are also invited to follow the specific human trafficking-focused elective course:  

Human trafficking: An approach from legal, policy and social science perspectives

This (Dutch-taught) elective, specially designed for Criminology and Law students, offers an interdisciplinary insight into the manifestations and approach to human trafficking. In five intensive seminars, motivated students delve into various aspects of human trafficking, including criminal and labour exploitation. The course addresses the relationship between the perception of trafficking and current policies, as well as the criminal justice and comprehensive approach to this complex problem. It also considers the challenges of human trafficking research and current debates on emerging forms of exploitation. Guest lecturers from the field, such as the National Rapporteur, the national public prosecutor, representatives of the Dutch Labour Inspectorate and various social and aid organisations, play a central role in this course. They build a bridge between science, policy and practice, allowing students not only to acquire theoretical knowledge, but also to gain insight into daily practice and policy challenges surrounding human trafficking.

Information on the course in the e-prospectus. 

Course Coordinator: Dr I. de Vries

Within the master's programme Criminology

In all criminology master’s programmes, students can choose to conduct research on human trafficking and exploitation for their master’s thesis. Our research team also frequently offers internships to students in the Criminology MSc programmes; more information on these internships can be found on the Criminology Career Course Brightspace page. 

Criminaliteit en Rechtshandhaving: Criminologie en Veiligheidsbeleid 

Human trafficking and exploitation are considered in various courses in this master’s programme, partly since these issues are so high on the agenda of both national and local government. Relevant policy is therefore discussed in various courses throughout the programme.   

In the courses Veiligheidsbeleid (Security) and Evaluatie van Criminaliteitsbeleid (Evaluating Crime Policy) students are invited to formulate a proposal for municipal policy, which could be policy on human trafficking and exploitation, as well as a proposal to evaluate the proposed policy.  

In Handhavingsstrategieën (Enforcement Strategies), students are required to conduct research for one of the parties involved in the field of enforcement and monitoring. In this past, this has included research for the Netherlands Labour Authority where students focused on monitoring and enforcement related to labour exploitation. 

Forensische Criminologie (Forensic Criminology) 

This master’s programme includes a course on forensic victimology, which discusses human trafficking and exploitation as a factor in the development of victim rights, legislation, and victim support.  

Post-Academic Courses

Advanced course: Current issues in human trafficking

During this one-day course, professionals will have the opportunity to advance their knowledge on human trafficking and keep abreast of the latest developments in the legal and policy fields. The course offers insights into questions such as: How is the approach to human trafficking shaped? What bottlenecks play a role in practice? What recent changes in legislation and guidelines are relevant? And what emerging forms of human trafficking are we not fully aware of? The sessions are taught by lecturers from Leiden University, in collaboration with guest lecturers from policy and practice. These experts offer a unique blend of scientific insights and practical experience, providing participants with both theoretical knowledge and practical tools.

See here for more information (in Dutch) on this advanced course on the website of Leiden Law Academy.

Specialisation course: Ondermijning (Subversive Crime) 

During this three-day course, participating staff from the Regional Information and Expertise Centre (RIEC) in The Hague discuss subversive crime, with a particular focus on local problems and the role of local authorities in dealing with this problem. Current issues receive special and extensive attention. Participants will obtain further insight into the various forms of subversive crime at the local level; the tasks and responsibilities of parties involved in tackling this problem; the various collaborative possibilities, given data protection considerations, and the particularities of specific forms of subversive crime, including the recruitment of young people by criminal networks and human trafficking more broadly. 

See here for more information (in Dutch) on this specialisation course on the website of Leiden Law Academy.

External seminars

Seminar on Human Trafficking and Victim Support in Europe

The differences in human trafficking figures within Europe are significant. Portugal has relatively few registered victims, while the Netherlands has considerably more. Behind these statistics lies a complex reality and the data are largely the outcome of efficient or less efficient registration practices. It is clear, however, that the different forms of exploitation take place everywhere. This was one of the topics discussed by speakers, students, and researchers at the Seminar on Sexual Crimes and Victimology at the Universidade Autónoma de Lisboa (UAL) in Portugal on April 8, 2025.

A large number of students from the Amsterdam study association Crime Does Pay (Vrije Universiteit) and several Portuguese students and staff attended the lectures. Professor Joanne van der Leun from Leiden University spoke about human trafficking and the exploitation of migrants in the EU. Additionally, there were contributions on the approach and legislation in Portugal. The Portuguese victim support organization APAV, celebrating its 35th anniversary this year, discussed the impact on victims and the coaching of victims. After the seminar, Joanne van der Leun explored with the rector and dean of UAL the possibilities of strengthening collaboration in this field.

Current projects

Images of human trafficking in policy and the media

What image of trafficking is portrayed in policy and media, and what implications might this have for policymaking? Several ongoing studies answer this question by analysing the content of policy documents, media items and interviews.

Researchers: Dr Ilse Ras, Dr Ieke de Vries, Dr Janne van Doorn, and trainee researchers
Contact: i.a.ras@law.leidenuniv.nl  

Looking beyond the victim: The role of the living environment in the sexual exploitation of minors and young adults

Summary: This four-year project examines the role of the living environment in preventing and tackling vulnerability to victimisation. This is done using qualitative analyses of, for example, criminal investigations and statistical analyses of, among others, data from Statistics Netherlands.

Researchers: Dr Ieke de Vries, Professor Arjan Blokland, Jasmijn Groen, Dominique van Meer
External funding: NWO Veni Grant [Dr Ieke de Vries]
Contact: i.de.vries@law.leidenuniv.nl

The role of the social environment in the sexual exploitation of minors 

Summary: This study examines how social isolation, social vulnerability and social resilience play a role in the sexual exploitation of child victims. It does so through a qualitative content analysis of chat data from Chat met Fier, an online platform where young people can talk anonymously about violence and dependency issues with online care professionals.

Researchers: Dr Ieke de Vries, Sjoerd van Bemmelen (Centre against Child and Human Trafficking), Sarah Ebrahem, Daan Donninger, Berber van der Meer

External funding: LUF [Dr Ieke de Vries]
Contact: i.de.vries@law.leidenuniv.nl

Victimisation experiences of young adults involved in organised crime (PhD research)

Summary: The aim of this research is to understand the experiences, life course and environmental factors of victims of criminal exploitation and young adults involved in organised crime. It also examines how these young people are treated by actors in the criminal justice chain and the impact of this identification on the course of their lives.

Researchers: Fallon Cooper (PhD candidate), Dr Ieke de Vries (Co-supervisor and day-to-day supervisor), Dr Babette van Hazebroek (Co-supervisor and day-to-day supervisor), Professor Maarten Kunst (Supervisor) & Professor Arjan Blokland (Supervisor).
External funding: Starting Grant [Dr Ieke de Vries]
Contact: f.i.cooper@law.leidenuniv.nl

Migrants’ Deportability in Mexico: Punishment and Deterrence

This research examines the experiences of populations on the move in Mexico. It examines how punishment and deterrence are articulated and expressed in the deportability of regularized migrants in Mexico across different facets of the migratory process: transit, regularization, and detention.

Researcher: Dr Amalia Campos-Delgado

Contact: a.e.campos.delgado@law.leidenuniv.nl

LA cuidadora: Latin American female migration and elderly home-care work in Europe

This project aims to examine the participation of Central American migrant women in the labour niche of in-home care for the elderly. In particular, it explores the case of Honduran migration to Spain and Salvadoran migration to Italy. We are interested in what kind of work arrangements they have, the type of relationships they maintain with the people they care for, how they cope with the care vacuum they leave behind in their countries of origin, and their expectations and possibilities for family reunification.

Researchers: Dr Amalia Campos-Delgado, Dr Mark Klaassen

Contact: a.e.campos.delgado@law.leidenuniv.nl

Tackling human trafficking and labour exploitation

Human trafficking is a complex phenomenon. Besides exploitation in the sex industry, it also involves labour exploitation in a broad sense. How different governments deal with it, what measures are taken and how these policies interact with migration policies is the subject of ongoing collaborations in research and education.

Researchers: Professor Joanne van der Leun, Professor Masja van Meeteren (Radboud University) and colleagues from other uiversities abroad.

Contact: j.p.vanderleun@law.leidenuniv.nl 

Recent publications

Bhimani, Shawn, Ieke de Vries, Aubrey Sneesby, Amy Farrell and Kayse Maass. 2024. The ties that link us: Uncovering the socio-technic connections of labor trafficking networks. Production and Operations Management (online first). doi.org/10.1177/10591478231224917. [article link – open access]

Campos-Delgado, Amalia. 2024. Euphemistic rhetoric and dysphemistic practices: governing migration in Mexico. Geopolitics 29(1), 64-89. https://doi.org/10.1080/14650045.2023.2185513

Campos-Delgado, Amalia and Côté-Boucher Karine. 2024. Tactics of empathy: the intimate geopolitics of Mexican migrant detention. Geopolitics 29(2), 471-494. https://doi.org/10.1080/14650045.2022.2039633

Campos-Delgado, Amalia and Yrizar Barbosa, Guillermo. 2023. Arbitrary detention of Mexican citizens by Mexican immigration authorities. International Journal for Crime, Justice and Social Democracy 12(2), 47-58. https://doi.org/10.5204/ijcjsd.2890

Cooper F.I., Bemmel S.R. van, Leun J.P. van der & Kunst M.J.J. (2024), Factors that influence the criminal justice response to human trafficking: a systematic review of North American and European studies, Crime, Law and Social Change 82(3): 623-658.

de Massol de Rebetz, Roxane. 2024. A review of the new Facilitation EU Directive Proposal in light of the unique Belgian approach to deal with migrant smuggling. Boom Strafblad 5(2): 110-115. 

De Vries, Ieke and Toby Davies. 2024. Understanding the role of street network configurations in the placement of illegitimately operating facilities. Criminology 62 (3), 412-453. https://doi.org/10.1111/1745-9125.12381. [article link – open access]

De Vries, Ieke, Michael Baglivio and Joan A. Reid. 2024. Examining individual and contextual correlates of victimization for juvenile human trafficking in Florida. Journal of Interpersonal Violence (online first). doi.org/10.1177/08862605241243332. [article link – open access]

Donninger, Daan*, Ieke de Vries, Ilse Ras and Masja van Meeteren. 2024. De beeldvorming van mensenhandel in het Nederlandse politieke debat [The framing of human trafficking in Dutch parliamentary debates – available in Dutch only]. Tijdschrift voor Criminologie 66 (1), 46-70. doi.org/10.5553/TvC/0165182X2024066001003 [article link – open access]

Koning, A., Ras, I. A., & van der Leun, J. P. (2024). Origin stories: Framing 25 years of Dutch political discourse on child sexual exploitation by tourists and travelers. European Journal of Criminology, 21(3), 370-391. https://doi.org/10.1177/14773708231208750

Meeteren M.J. van & Leun J.P. van der (2024), How organized is labour trafficking?: On the involvement of organized criminal groups in labour exploitation. In: Rodrigues A.M. & Guia M.J. (red.), New forms of human trafficking: Global South highlights and local contexts on sexual and labor exploitation. Cham: Springer. 239-254.

Ras, I. A., & Koning, A. (2024). The disappearance of ‘poverty’ in Dutch House of Representatives debates on the sexual exploitation of children in travel and tourism (SECTT). Discourse & Society, 0(0). https://doi.org/10.1177/09579265241288586 

Rossoni, I. (2024) Understanding EU Funding of Anti-Trafficking Initiatives: Where is the money (not) going?.  Anti-Trafficking Review, (23), 98–118. https://doi.org/: 10.14197/atr.201224236.

Rossoni, I., Büyükkalkan, O., & Erken, U. (2024). An Image Is Worth a Thousand Words: Exploring Visual Imagery About Trafficking in the Online Domain – an Italian Case Study. Journal of Human Trafficking, 1–23. https://doi.org/10.1080/23322705.2024.2335872

Rossoni, I., & de Massol de Rebetz, R. (2025). The Convenient Villain and the Stereotypical Victim: How Demand and Vulnerability Help Construct Anti-Policies in Trafficking and Smuggling. Journal on Migration and Human Security, 0(0). https://doi.org/10.1177/23315024251316543