The study, developed by Tax Justice Network ranks countries by their involvement in corporate tax avoidance and placed The British Virgin Islands, Bermuda and the Cayman Islands at the top of the list.
Christian Aid claims the tax rules for UK Overseas Territories is negatively impacting the poor, as they encourage big companies to avoid paying taxes.
Low tax revenues have forced developing countries to make cuts to health care, education and other public services and Christian Aid is calling on the UK government to intervene.
Toby Quantrill, Christian Aid's Global Lead on Economic Justice told Premier: "[Multinationals] can shift the profits that they make to another jurisdiction, which has a much lower tax rate.
"And this has a huge impact on the ability of those countries to provide for their students in terms of education and health."
Mr Quantrill says the government needs to tighten tax laws to prevent big businesses from exploiting the poor: "They're providing the opportunity for companies to rob other countries of tax revenues."
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