Over €5bn that was promised for Ebola hit West Africa cannot be traced - according to Oxfam.
The charity has said more than a billion has not been delivered at all, and little is known about the rest.
Sierra Leone was declared Ebola free in November, but earlier this month a woman in the country died of the disease.
Thynn Thynn Hlaing is the charity's director there, and has said prevention remains essential.
“This country has a history like every two years they have different outbreaks.
“So like three years ago we suffered from Cholera outbreak and after two years we suffer from Ebola outbreak.
“So it is very important to work with the community.”