Barriers to prosecutions and convictions under the Modern Slavery Act 2015

By Anna Skeels

This report is the first part of a two-part series based on research conducted by Dr Alicia Heys, a Senior Lecturer in Modern Slavery at the Wilberforce Institute at the University of Hull and – on behalf of it – a Co-Investigator of the Modern Slavery and Human Rights Policy and Evidence Centre (PEC) at the University of Oxford, as part of the research strand focused on the effectiveness of legal enforcement measures. The first part focuses on barriers to successful modern slavery prosecutions, whilst the second part focuses on financial investigations as a method of pursuing modern slavery offenders. Both reports, when published, will be available on the PEC website at modernslaverypec.org/resources/prosecutions-modern-slavery-act.  The Modern Slavery Act (MSA) 2015 was introduced to strengthen the UK’s response to human trafficking and modern slavery, providing comprehensive tools to identify offenders, secure convictions, and protect victims.1 However, while the number of victims identified and referred to the National Referral Mechanism2 has continued to increase, prosecution and conviction rates under the Act remain notably low, raising questions about barriers to its implementation. This report examines some of these barriers, drawing on insights from practitioners directly involved in modern slavery cases, as well as academic and grey literature on the subject. The original research informing this report aimed to explore how financial investigations could improve prosecution and conviction rates under the Modern Slavery Act. Fifteen in-depth interviews were conducted with specialists including seven police officers based in English forces, three lawyers, three financial experts, one international cyber-crime expert, and one NGO representative with lived experience of modern slavery. All interviews were anonymised, transcribed, and analysed thematically. Given the breadth and depth of the data collected, the key findings are presented in a two-part series. The first part, summarised in this report, focuses on identifying and analysing key barriers to successful prosecutions and convictions under the Modern Slavery Act. By integrating practitioner perspectives with academic and grey literature, this report aims to inform efforts to strengthen the enforcement of modern slavery legislation in the UK.3 The second part will build on the same interview data, but with a specific focus on financial investigations as a method of pursuing modern slavery offenders.4 

Oxford, UK: Modern Slavery and Human Rights Policy and Evidence Centre (PEC) at the University of Oxford , 2025. 41p.