Returning the Home State to the Global Anti-Corruption Campaign

International investment law is facing significant challenges in combating corruption in investment activities. The existing scholarly discussions are mostly centred upon the triangular relationship between the foreign investor, the host State and the investment arbitration tribunal. The role of another important body—the home State—has been under-examined, which seems to be better placed to implement measures to effectively govern investors’ (mis)conduct and ensure responsible investments. After identifying the low rate of substantiated corrupt acts in investment arbitration and the lack of a robust corruption prevention system in investment treaties, this article argues that participation of home States in arbitration proceedings can help mitigate those arduous evidentiary challenges and facilitate the fact-finding process. Home States should also impose obligations of delivering periodic corruption risk assessments on investors through domestic legislation and investment treaties.