A New One Report which exposes corruption in developing countries. It argues that more than 3.5 million lives a year could be saved if the G20 cracked down on the corrupt business practices, money laundering and tax evasion that cost the world’s poorest countries at least a trillion dollars a year. It focuses on use of developing countries for tax evasion by multinationals. See some analysis of this report on the Conversation blog.
Another site which has reports and data on international corruption is Transparency International. See its reports on activities of multinationals.
The Tax Justice Network has reports on data on tax havens and activities of multinationals. It also produces The Financial Secrecy Index which ranks jurisdictions according to their secrecy and the scale of their activities
The IMF has some recent reports on spillovers in international corporation taxation examining the impact of tax practices on developing countries.
OECD base erosion and profit shifting project focuses on areas including recommendations regarding the design of domestic and tax treaty measures to prevent abuse of tax treaties
Eldis links to reports from development NGOs and agencies on related topics. See this 2008 paper by Christian Aid