A total of 51 out of 68 companies that receive such funds from the International Finance Corporation for sub-Saharan Africa used tax havens.
And they accounted for 84 per cent of IFC investment in the region in 2015, Oxfam said in a report yesterday.
The use of the havens had no apparent link to the companies' core business, it added.
The most common haven for these companies was Mauritius, Oxfam said, adding that 40 per cent of the IFC's customers investing in sub-Saharan Africa had ties there.
More From This Section
The Oxfam report comes in the wake of the Panama Papers leak about how wealthy individuals and firms use tax havens to hide assets and avoid paying taxes.
"It doesn't make sense for the World Bank Group to spend money encouraging companies to invest in 'development' while turning a blind eye to the fact that these companies could be cheating poor countries out of tax revenues that are needed to fight poverty and inequality," said Oxfam's tax policy advisor, Susana Ruiz.
It has risen from USD 1.20 billion in 2010 to USD 2.87 billion in 2015, the study said.