* Liberian man died of the disease on Friday, ministry says
* He fell ill on arrival on Sunday, was isolated in a hospital
* Ebola has killed 660 people in West Africa (Adds WHO hasn't had results back)
By Felix Onuah and Tom Miles
ABUJA/GENEVA, July 25 (Reuters) - A Liberian man who died in Nigeria's commercial capital Lagos on Friday tested positive for the deadly Ebola virus, Health Minister Onyebuchi Chukwu said.
Patrick Sawyer, a consultant for the Liberian finance ministry in his 40s, collapsed on Sunday after flying into Lagos, a city of 21 million people, and was taken from the airport and put in isolation in a local hospital. Nigeria confirmed earlier on Friday that he had died in quarantine.
"His blood sample was taken to the advance laboratory at the Lagos university teaching hospital, which confirmed the diagnosis of the Ebola virus disease in the patient," Chukwu told a press conference on Friday. "This result was corroborated by other laboratories outside Nigeria."
However, at a separate press conference held by the Lagos state government at the same time, the city's health commissioner, Jide Idris, said that they were only "assuming that it was Ebola" because they were "waiting for a confirmative test to double check" from a laboratory in Dakar.
Paul Garwood, spokesman for the World Health Organisation (WHO) in Geneva, said the U.N. health agency was also still waiting for test results.
"We're still waiting for laboratory-confirmed results as to whether he died of Ebola or not," he said.
It could not be immediately determined why there was a contradiction in the comments from central government and city officials.
If confirmed, the man would be the first case on record of one of the world's deadliest diseases in Nigeria, Africa's biggest economy and with 170 million people, its most populous country. Ebola has killed 660 people across Guinea, Liberia and Sierra Leone since it was first diagnosed in February.
Sawyer was quarantined on arrival and had not entered the city, a Nigerian official told Reuters.
"While he was quarantined he passed away. Everyone who has had contact with him has been quarantined," the official said.
Liberia's finance minister Amara Konneh said Sawyer was a consultant for the country's finance ministry.
"Our understanding is that the cause of death was Ebola," Konneh told Reuters.
The victim's sister had died of the virus three weeks previously, and the degree of contact between the two was being investigated by Liberian health ministry officials, he said.
Earlier on Friday, WHO spokesman Paul Garwood said: "I understand that he was vomiting and he then turned himself over basically, he made it known that he wasn't feeling well. Nigerian health authorities took him and put him in isolation."
Nigeria has some of the continent's least adequate healthcare infrastructure, despite access to billions of dollars of oil money as Africa's biggest producer of crude.
Some officials think the disease is easier to contain in cities than in remote rural areas.
"The fear of spread within a dense population would be offset by better healthcare and a willingness to use it, easier contact tracing and, I assume for an urban population, less risky funerary and family rites," Ian Jones, a professor of virology at the University of Reading in Britain, said.
"It would be contained more easily than in rural populations."
There have been 1,093 Ebola cases to date in West Africa's first outbreak, including the 660 who have died, according to the WHO.
(Reporting by Tom Miles; Additional reporting by Tim Cocks and Oludare Mayowa in Lagos, Kate Holtan in London, Clair MacDougall in Monrovia, Emma Farge in Dakar and Stephanie Nebehay in Geneva; Writing by Stephanie Nebehay and Tim Cocks; Editing by Susan Fenton and Sonya Hepinstall)