Sierra Leone said on Tuesday that it had mistakenly reported an Ebola positive case in Kailahun, a former hotspot for the virus which has not seen a case for nearly four months.
A nine-month-old baby was pronounced Ebola positive last week but was later found to have died from other causes, according to National Ebola Response Centre spokesman Sidi Yahya Tunis.
He blamed the mistake on a "lapse" by health officials who took the blood sample from the corpse.
Kailahun, which borders Guinea, was the first district in Sierra Leone to report a case of the hemorrhagic fever last May and at its peak recorded around 80 cases a week.
Nearly 3,800 people have died of Ebola in Sierra Leone as a whole but numbers are falling as steps to control the disease take hold.
Kailahun district council chairman Alex Bonapha said the false test result had resulted in deaths at a local clinic where medical staff were quarantined as a precaution, "leaving the patients without care."