The International Crimes Tribunal Bangladesh (ICTB) was set up by Bangladesh through the adaptation of the International Crimes Tribunal Act 1973, as an internal mechanism trying to prosecute and punish Bangladeshi perpetrators who committed international crimes in Bangladesh liberation war in 1971. After a long disappearance from the public eye, the Tribunal was reemerged in 2010. The recent cases decided by the Tribunal have revealed that the international crimes; namely, crimes against humanity, were allegedly committed in 1971, while the relevant Statute was enacted in 1973, and was implemented in 2010. Recently, the ICTB is prosecuting crimes against humanity retroactively, which might have violated the prohibition of penalizing certain conducts committed by the perpetrators before the enforcement of such conduct as a law banning such demeanor as an offense. Therefore, this study firstly analyzes the rule against retroactivity in international criminal law. Secondly, it investigates the justification of the retroactive criminalization of crimes against humanity at the first International Military Tribunal, Nuremberg, and its crystallization into the regional and international legal instruments. Thirdly, the study examines the characteristics of crimes against humanity as an international crime, to scrutinize whether the ICTB needs to fulfill such requirements either in 1971 or 2010. Then, it illustrates various judgments of the ICTB, demonstrating that it does not comply with the rule prescribed by international laws either in 1971 or 2010, in prosecuting crimes against humanity retroactively. Lastly, the study concludes by forwarding ways necessary to the ICTB in retroactive prosecution of international offenses.

Bangladesh is recently prosecuting and punishing the perpetrators of crimes against humanity and genocide committed in the Liberation War of 1971 via a domestically operated tribunal, namely the International Crimes Tribunal Bangladesh (ICTB). Though the Tribunal is preceded under municipal law, its material jurisdiction, i.e., crimes against humanity and genocide, originated from international criminal law. Therefore, this study examines several legal obligations of the ICTB in defining crimes against humanity and genocide as the core international crimes. First, I discuss several legal flaws of the Tribunal by defining crimes against humanity and genocide under the ICTB Statute and jurisprudence. Second, I scrutinize the legal status of international (treaty and customary) laws in Bangladesh’s legal system. Third, by applying international criminal law standards, I focus on the idea that it is one of the obligations of Bangladesh to apply international criminal law definitions of genocide under the treaty obligation as the contracting parties to Genocide Convention 1948, and the ICC Statute 1998. Fourthly, I also discuss whether Bangladesh has any obligation to apply customary international law definition of crimes against humanity because crimes against humanity are considered jus cogens offenses in general international law, from which no derogation is permitted. Lastly, I conclude that Bangladesh Tribunal failed to fulfill its legal obligation to define international crimes under the treaty and customary laws and forward a way to be implemented to improve the legislative system of Bangladesh and harmonize it with international legislation.

Bangladesh is recently prosecuting and punishing the perpetrators of crimes against humanity and genocide committed in the Liberation War of 1971 via a domestically operated International Crimes Tribunal Bangladesh (‘ICTB’). Though the Tribunal is preceded under the municipal law, it's material jurisdiction, i.e., crimes against humanity and genocide are originated from international criminal law. Therefore, this study purposes to examine several legal obligations of the ICTB in defining crimes against humanity and genocide as the core international crimes. Firstly, I scrutinize what is the legal status of international law (treaty and customary law) in Bangladesh's legal system? Secondly, by applying international criminal law standards, I focus on that is it one of the obligations of Bangladesh to apply international criminal law definitions of genocide under the treaty obligation as the contracting parties to Genocide Convention 1948, and the ICC Statute 1998? Thirdly, I also discuss whether Bangladesh has any obligation to apply customary international law definitions of crimes against humanity because crimes against humanity are considered as jus cogens offense in general international law, from which no derogation is permitted. Lastly, after a critical evaluation of domestic and international criminal law instruments, I conclude that Bangladesh certainly failed to fulfill its legal obligation to define international crimes under a treaty and customary laws, which is one of the fatal errors of the ICTB, a government-sponsored criminal tribunal, to secure criminal justice to the accused.