A Nigerian woman who died suffering from flu symptoms has tested positive for the deadly H5N1 strain of the avian flu virus, says a government minister.
Many Nigerians earn their living from the poultry trade
It is the first bird flu death reported in sub-Saharan Africa since it surfaced in Nigeria a year ago.
The victim was a 22-year-old from the commercial capital, Lagos.
Health officials said inconclusive tests had also been carried out on her mother and two other people, all of whom died recently.
"Last night our team of 13 scientists were able to conclusively identify the case of avian influenza," Nigerian Information Minister Frank Nweke Jnr told a news conference in Lagos.
He said blood samples were now being sent to foreign laboratories and the findings are now with the World Health Organisation for further scrutiny.
More than 160 people have died of H5N1 bird flu since its outbreak in December 2003 - most of them in South-East Asia
The UN had expressed concerns about the Nigerian government response to the disease - as poultry are still being moved around by local farmers despite an official quarantine and promised compensation for infected birds.
Quarantines have not been working
It is understood that the dead woman bought the infected chickens from a local farmer.
Dr Abdulsalam Nasidi, leader of Nigerian government's team of experts on bird flu, told the BBC News website that those that contracted the virus were those that had been dealing with the killing and preparation of the chicken and not those that ate it
"This goes to show that properly cooked chicken is safe, but handling infected birds can be hazardous," he said
Cross-infection to humans is relatively rare and usually occurs where people have been in close contact with infected birds.