A leading scientific journal has reported the World Health Organisation (WHO) will now endorse the use of the banned agricultural chemical DDT to control malaria-carrying insects.
A six-year ban on DDT has been effectively enforced by international aid agencies, amid a debate on the balance between malaria risks and environmental effects.
As malaria rates rose, advocates of interior house spraying accused Western aid agencies of ignoring the deaths of more than 800,000 children a year.
University of Melbourne School of Medicine head, Professor Graham Brown says findings about DDT's damage to the environment and health were connected with mass agricultural use.
"However, they were not balanced against the benefits in term of lives saved through use of this in a careful way," he said.
The United States Agency for International Development (USAID), the government agency providing US economic and humanitarian assistance worldwide for more than 40 years, will now fund the use of DDT.
The journal Nature Medicine reports that the WHO guidelines will be changed to endorse its wider use.
Greenpeace scientists say they are still opposed to any easing of the restrictions on DDT.
Dr David Santillo from the Greenpeace research laboratories at the University of Exeter says that USAID's decision to fund the use of DDT is worrying.
"That certainly raises some quite substantial concerns and if there's substantial funding coming from the US to support that, then that does sound very much like a step in the wrong direction," he said.
"I think where that funding is better placed is in developing the availability of alternative strategies."