About a quarter of countries in sub-Saharan Africa receive little funding for research into malaria despite having high death rates.
This is according to a study on Thursday that highlighted the unequal spread of resources to tackle the disease.
The study by Britain's University of Southampton said no research investment could be found in Chad, Congo and Central African Republic, where malaria deaths are some of the highest in the region, or in Sierra Leone and Mauritania.
All countries received non-research funding which is designed to control malaria by investing in bed nets, public health schemes, and anti-malarial drugs.
Michael Head, who led the study, said this was the first study to examine the geography of public and philanthropic research funding for malaria.
"We've shown that there are countries that are being neglected ... and we need to alter the capacity for research in underfunded countries," Head told the Thomson Reuters Foundation.
The world has made huge strides against malaria since 2000, with death rates plunging by 60 per cent and at least six million lives saved globally, the World Health Organization (WHO) says.
But efforts to end one of the world's deadliest diseases - which kills about 430,000 people a year, mostly children in sub-Saharan Africa - are under threat as mosquitoes become increasingly resistant to measures such as bed nets and drugs.
The British university study was based on an analysis of funding data from 1997 to 2013 from 13 major public and philanthropic global health funders.
It found the countries that received the most research funding were Tanzania,
Kenya, Uganda, Malawi and Ghana.
Two funders provided almost 60 per cent of this funding. These were the US National Institutes of Health and the Bill & Melinda Gates Foundation.
Nigeria, Tanzania,
Kenya, Ethiopia and Malawi received the most non-research funding.
ALMA, a coalition of African heads of state and governments, aims to achieve a malaria-free Africa by 2030.
Head said the disparity can be partly explained by the fact some countries in sub-Saharan Africa do not have an established research infrastructure so it was hard to invest there.
"Ultimately, however, there are neglected populations in these countries who suffer greatly from malaria and other diseases," Head said.
"Investments in health improve the wealth of a nation and we need to be smarter with allocating limited resources to best help to reduce clear health inequalities."