Introduction Environmental crime often extends beyond a single nation’s jurisdiction. In particular, experience in the Indonesian forestry sector has highlighted the role of overseas financiers, trade and banking institutions. Moreover, pressing regional issues such as transboundary haze, illegal wildlife and timber trade, and increasing regional investment, have underscored the need for improved, collaborative approaches to enforcement. Notably, mutual legal assistance (MLA) agreements provide opportunities for gathering and exchanging information (witnesses, statements and evidence) among partner countries. In the context of forest govcernance, MLA potentially allows enforcement agencies to access the financiers and masterminds of illegal forest activities, that often span jurisdictions. Based on a literature and legal review, and interviews with Indonesia’s central authority for mutual legal assistance 1 , other key government officials 2 and focus group 3 discussions, 1 Indonesia’s central authority for mutual legal assistance is the Ministry of Law and Human Rights under the Directorate of International Law and Central Authority. 2 Attorney General Ofce, Anti-Corruption Commission, Ministry of Foreign Afairs, Ministry of Law and Human Rights, and University of Trisakti. 3 Interpol Indonesia, Ministry of Law and Human Rights, Anti-Corruption Commission, Ministry of Foreign Afairs, PPATK, Transparency International Indonesia and Trisakti University. we review Indonesia’s use of MLA to allow law enforcement agencies to access witnesses, information, evidence and assets in other countries. Despite considerable challenges to regional environmental cooperation among the Association for Southeast Asian Nations (ASEAN) (Jones and Smith 2007; Elliott 2010), MLA represents a realistic collaborative opportunity to help strengthen forest governance in the region. The importance of MLA to addressing forest-related crimes is increasingly recognized, and there are compelling reasons for pursuing collaborative enforcement beyond single jurisdictions (Walters 2010; Government of Indonesia 2013). Notably, localized environmental degradation has the potential to impact the broader region, and so merit increased regional collaboration. For example, Singapore’s new Transboundary Haze Pollution Bill will hold companies liable for fires in Indonesia that result in transboundary haze (Government of Singapore 2014). In fact, regional environmental cooperation is enshrined in a number of ASEAN agreements (Elliott 2010), which further highlights the potential and need for greater cooperation. This is particularly important because many regional environmental challenges also go hand-in- hand with regional trade links of timber and other wildlife (Smith et al. 2007; UNODC 2010, 2013; Nguyen 2012). In these types of cases, MLA is particularly well-suited to help enforcement agencies across jurisdictions to access information, evidence and suspects internationally (see Box 1). Key points • With diverse transboundary links in environmental crimes increasingly prominent, there is a need to identify tools to enhance international or regional cooperation in order to strengthen forest enforcement. • Mutual legal assistance (MLA) has particular potential to facilitate cooperation across jurisdictions. • Provisions on dual criminality and predicate offenses often limit the scope for MLA on forest-related crimes, both within Indonesia and in partner countries. • Proactive establishment of bilateral MLA agreements could strengthen MLA use, including with countries where the financiers and traders often reside and bank. • Existing platforms provide opportunities to operationalize country commitments to international cooperation on environmental topics. Mutual legal assistance to strengthen Indonesia-ASEAN forest governance Anna Christina Sinaga, Jacob Phelps, Dadang Trisasongko and Muji Kartika Rahayu No 77, August 2014 cifor.org CIFOR infobriefs provide concise, accurate, peer-reviewed information on current topics in forest research