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Our Team

We are a global programme of Transparency International, focused on tackling corruption in the global defence and security sector. Our staff and senior advisors bring expertise from their military, legal, diplomatic, academic and anti-corruption backgrounds to foster and promote global best practice on defence anti-corruption and to push globally for meaningful reform.

To join our team, view our vacancies here.

To read about our NAKO colleagues in Ukraine, visit NAKO’s website.

Read more about our team and their bios below.

Josie Stewart

Defence and Security Programme Director

As Director of Transparency International’s Global Defence and Security Programme, Josie leads a team working towards a world where governments, the armed forces, and arms transfers are transparent, accountable, and free from corruption. She has previously worked for and with governments, donors, multilateral institutions, law enforcement, military, civil society and the private sector, and brings expertise focused on corruption and illicit finance, conflict and security, and international development and diplomacy – as well as a deep passion for making a difference in the world. Josie is an Associate Fellow of the Royal United Services Institute (RUSI), and has lived and worked in Liberia, Sierra Leone, South Sudan, Afghanistan, and the UAE. She also serves on the Board of Spotlight on Corruption.

Ara Marcen Naval

Head of Advocacy

Ara Marcen Naval leads global advocacy for Transparency International Defence & Security, working towards raising awareness of the nexus of corruption, conflict and insecurity. Ara is a human rights specialist who previously work as Deputy Director for Global Issues at Amnesty International, where she headed up the organisation’s global research, campaigning and advocacy on issues including the arms trade, torture trade, policing weapons, and the use of inhumane weapons around the world and other disarmament related issues.

Michael Ofori-Mensah

Head of Research

Michael is Head of Research at Transparency International – Defence & Security (TI-DS) where he leads the design and delivery of TI-DS’s global research agenda. He previously managed the production of the Government Defence Integrity Index (GDI) 2020. Prior to joining TI-DS, Michael was Director of Research at the Institute of Economic Affairs (Ghana) where he spent 8 years leading research and coordinating a broad range of national and international projects. He has contributed to several public policy reform initiatives in the area of governance and constitution review. Michael has also provided technical support to key institutions, including Ghana’s Parliament, which he has advised on legislation such as the Presidential (Transition) Act. He has authored several publications on institutional reform, anti-corruption and public financial management. Michael holds a PhD from the University of Edinburgh, an MSc (Econ) in Political Economy from the London School of Economics (LSE) and a BA (Hons) in Economics and Politics from the University of Kent.

Colby Goodman

Senior Researcher (US)

Colby Goodman is a Senior Consultant at Transparency International Defence and Security (TI-DS) and an expert commentator on US security assistance abroad. At TI-DS, he conducts research and provides advice on corruption risks within the international arms trade and other forms of external assistance to defense forces.

Mr. Goodman has fought to reduce corruption risks and prevent harm in US security assistance over the past 15 years by uncovering some of the deeper challenges and illuminating ways to address these challenges. Three-parts policy sleuth and one-part advocate, he exposed key corruption-related risks in US counterterrorism aid and in changes to US controls on commercial arms sales as the former Director of the Security Assistance Monitor program. Government officials or congressional staff have used his insights to stop illegal trafficking networks in Africa, enhance US oversight over gifts of US military weapons and training, and push for effective controls on commercial arms sales around the world.

Najla Dowson-Zeidan

Advocacy and Engagement Manager

Najla joined Transparency International Defence & Security in September 2017 as a Project Manager in the Conflict and Insecurity team. She works on projects related to tackling corruption in the defence and security sectors in fragile and conflict-affected states, with a focus on the Middle East and North Africa. Prior to joining Transparency International, Najla managed media development, governance, and humanitarian-related research projects across the Middle East and North Africa region for BBC Media Action, an international development organisation. She holds an MA in Human Rights Law from SOAS, University of London and speaks Arabic.

Mohamed Bennour

Programme Manager

Mohamed works on projects related to strengthening accountability and transparency in the defence sector together with national chapters across the West Africa and MENA region. Before joining TI, up to 2021, Mohamed worked with Options Consultancy as a Senior Programme Manager and Technical Advisor on sexual and reproductive health and rights programmes across West Africa and Asia. Mohamed has also worked with Oxfam in Tunisia in various programme roles on issues relating to governance of public policies, fiscal justice, gender justice, civic space and youth empowerment.

Patrick Kwasi Brobbey

Research Project Manager

Dr. Patrick Kwasi Brobbey is a Research Project Manager – Government Defence Integrity Index (GDI) responsible for managing the production and the delivery of the GDI. Patrick is a politics and international development expert who specialises in public opinion formation, governance, conflict, and peacebuilding. Prior to joining Transparency International, Patrick was an LSE Fellow at the Department of Methodology at the London School of Economics and Political Science (LSE), where he conducted independent research and taught on methodology courses designed for social science research, in general, and politics and international development research, in particular. He has also served as a Research and Evaluation Consultant for organisations like World Vision International, International Organization for Migration (IOM), and International Civil Society Action Network (ICAN) and has provided strategic advice on aspects of Kenyan elections to concentrate financial and technical assistance to the Governance Team, DFID Kenya and the Donor Group on Elections. Patrick’s work has yielded academic, policy, and journalistic publications. He holds a PhD in African Studies from the University of Edinburgh, an MA in Political Science from McGill University, and a BA (First Class Hons.) in Sociology with Political Science from the University of Ghana.

Sabrina White

Defence and Security Gender Specialist

Dr. Sabrina White is a gender specialist at Transparency International Defence and Security. She holds a PhD from the University of Leeds and was recipient of an Economic and Social Research Council Grant to investigate accountability for sexual misconduct in UN peacekeeping operations. Her work focuses on gender, integrity systems and anti-corruption measures in the defence and security sectors. She has contributed to academic and NGO publications, including for the U4 Anti-Corruption Resource Centre, the European Journal of International Security, and several books. Sabrina has worked with the UK government’s Protection from Sexual Violence Initiative, contributing in consultations with the United Nations Association-UK to the development of the Murad Code and on action on sexual exploitation and abuse in UN peacekeeping. She has also taught at Regent’s University London, the University of Leeds, Leeds Beckett University and at various summer programmes at universities in Thailand and Sierra Leone.

Giulio Morucci

Monitoring, Evaluation and Learning Manager

As MEL Manager, Giulio designs and implements data-capturing and reporting systems for the Defence and Security programme. Before joining TI-UK in 2023, he worked in consultancies providing Monitoring, Evaluation and Learning services to FCDO and EU-funded projects in fragile and conflict-affected areas. He holds a Master’s in Political Economy of Late Development from the London School of Economics.

Léa Clamadieu

Research Project Officer

Lea is a Research Project Officer for the 2025 Government Defence Integrity Index (GDI). Prior to joining us, she was a Defence Budgets and Forecast Analyst at Janes - a defence open-source intelligence company based in London. Lea holds a MA in International Peace and Security from King's College London and a BA in European Studies from University College London.

Irasema Guzman Orozco

Research Project Officer

Irasema is a Research Project Officer for the Government Defence Integrity Index (GDI). She is a researcher specialising in corruption and governance. She completed her PhD in Politics at the University of Sussex where she made significant contributions to the Centre for the Study of Corruption. Her doctoral project employed mixed methods to explain the power dynamics facilitating corruption risks in public procurement. Irasema also has extensive experience working in the Mexican public sector, which includes leading projects that enhanced fiscal transparency and public participation.

Denitsa Zhelyazkova

Research Officer

Denitsa is responsible for conducting qualitative and mixed-methods research projects, producing and facilitating literature reviews, synthesis studies and case-based studies on key topics. She holds a Bachelor of Social Sciences in Politics and International Relations from the University of Manchester and has previously worked as Junior Research Executive at YouGov as well as a policy intern for the Administration of the President of Bulgaria at the Unit of Strategic Policies, Analyses and Prognoses.

Michael Picard

Research Fellow (US)

Michael is a Graduate Research Fellow supporting Transparency International’s Defence and Security team in Washington, DC. He has extensive research experience in arms control and proliferation – specifically small arms and light weapons – and has worked for the Small Arms Survey, the University of Sydney’s School of Public Health, the Centre for Armed Violence Reduction, and others. His past research has focused on the small arms trade and armed violence in Southeast Asia, where he has conducted field research and written about the subject. In addition to his research background, Michael is also an officer in the Swiss Army. He is currently pursuing a master’s degree at Johns Hopkins University’s School of Advanced International Studies in Washington, DC, with concentrations in International Economics and Conflict Management.

Emily Wegener

Evidence and Advocacy Officer

Emily works on advocacy and research across both TI Defence & Security, having previously held the position of Research & Reporting Officer within TI Global Health. Her main responsibilities include supporting the development of research publications, blogs and advocacy materials, conducting research, and coordinating initiatives across the international programmes. Emily holds a Masters degree in International Development from the University of Manchester and has previously gained work experience in Germany, Kenya and Uganda.

Yi Kang Choo

Programme Officer

Yi Kang is responsible for enabling Transparency International Defence and Security to operate efficiently and effectively, by delivering rigorous operational and programme administration support across our global portfolio. He is dedicated to the mission to strengthen transparency, accountability and oversight systems in a traditionally opaque and secretive sector.

Yi Kang brings in multi-sectoral expertise, having being part of a wide range of civil society organisations, charities, and international law firms. He holds a Masters in Corporate Law from the University of Cambridge and a LLB Law Degree from the Queen’s University of Belfast. Yi Kang speaks Mandarin, Cantonese and Malay.