A person who died in a suspected case of Ebola in Nigeria, triggering a scare and the quarantine of 10 others, did not have the deadly virus, according to World Health Organization spokesman Gregory Hartl.
"(The) dead person tested negative for Ebola. So this person is not going to be the source of an Ebola event," Mr Hartl said.
A laboratory investigation showed the dead person did not have Ebola or Lassa fever, Mr Hartl said.
Meanwhile, a Scottish nurse who is being treated for a late complication of the Ebola infection is in a "serious condition", the hospital treating her has said.
Pauline Cafferkey was flown from Glasgow to an isolation unit at the Royal Free Hospital in Hampstead, northwest London, in a military aircraft in the early hours of the morning.
The hospital said she is in a "serious condition" in the special unit.
Bodily tissues can harbour the Ebola infection months after the person appears to have fully recovered.
An earlier statement from the Royal Free said: "We can confirm that Pauline Cafferkey was transferred from the Queen Elizabeth University Hospital in Glasgow to the Royal Free London hospital in the early hours of this morning due to an unusual late complication of her previous infection by the Ebola virus.
"The Ebola virus can only be transmitted by direct contact with the blood or bodily fluids of an infected person while they are symptomatic, so the risk to the general public remains low and the NHS has well-established and practised infection control procedures in place."
People who have been in close contact with her are being monitored by Scottish health authorities as a precaution.
