According to the websites, scientists worry that the counterfeit medications could harm patients and lead to drug resistance among malaria parasites.
Researchers studied fake and poor quality anti-malarial drugs on sale in 11 African countries between 2002 and 2010.
The tablets contained mixtures of the wrong pharmaceutical ingredients – and would only relieve symptoms, not cure the malaria.
Some of the fake tablets are believed to have originated in China, the BBC News said.
Lead researcher Dr. Paul Newton told the news site that failure to take action would put millions of lives at risk, especially children and pregnant women.