The latest in a series of setbacks has hit research on how effective the drug tenofovir is at stopping the HIV virus from infecting people in high-risk populations.
On 11 March, Family Health International announced it was cancelling tenofovir trials among Nigerian sex workers. The non-profit organisation cited problems with record keeping and other technical issues.
One day earlier, a separate trial of the drug due to take place in Thailand was criticised by local activists who claimed the research, involving injecting drug users, was unethical.
In 2004, Cambodia suspended trials of tenofovir following similar protests, and in February 2005, Cameroon also ended a trial of the drug (see Cameroon suspends trial of AIDS drug after protests).
Other trials of tenofovir are under way in Ghana and Malawi.Link to full news story in Science
Read more about research ethics in SciDev.Net's ethics of research dossier.