Sierra Leone health officials on Sunday announced that a dead woman tested as Ebola positive a week after the last known patient to suffer from the disease in the country was released from hospital
The 67-year-old woman recently died in the Kambia District in the northern part of the country.
Sierra Leone's chief medical officer Brima Kargbo told Reuters that Kambia did not encounter any Ebola cases for 50 days, which may suggest an error in the test results.
If confirmed, this would mean that further efforts are required to terminate the 18-month epidemic that has infected more than 28,000.
According to the World Health Organisation, the current Ebola outbreak - which started in December 2013 - killed more than 11,000 people mainly, in Liberia, Sierra Leone and Guinea.
Kargbo said the Ebola positive woman was a trader, however her acquaintances said she had not travelled recently.
The medical officer also said further tests were being carried out in several other cities.
Before this case, Sierra Leone had been in a 42-day countdown to be declared Ebola free.