Health minister Onyebuchi Chukwu said that a senior doctor who treated Nigeria's first Ebola patient has died, taking the death toll in Africa's most populous country to five.
Chukwu said the doctor was "the most senior who participated in the management of the (first Ebola) patient" in the country.
Liberian-American Patrick Sawyer, 40, died in a Lagos hospital on July 25, five days after arriving at the city's airport visibly unwell on a flight from the Liberian capital, Monrovia.
"With this unfortunate development, the total number of Ebola virus-related deaths in Nigeria now stands at five," Chukwu added.
The four other deaths included two medical workers, a doctor and a nurse, who had treated the Liberian finance ministry consultant, and an official from the west African regional bloc, ECOWAS, who picked him up from the airport.
All of the cases have been in Lagos, which is sub-Saharan Africa's biggest city with more than 20 million people.
The World Health Organization said Tuesday that there were 15 cases of the virus in Nigeria.
The global death toll from Ebola stands at 1,229, with the bulk of cases in Liberia, Guinea and Sierra Leone.