She was taken for tests after showing signs of the deadly infection which is affecting large parts of West Africa.
The woman, who is understood to have arrived from Sierra Leone, was being held at Dungavel Detention Centre in South Lanarkshire. The Home Office suspended the movement of detainees while the investigation was carried out. NHS Lanarkshire said the tests were a precautionary measure, adding that it was "highly unlikely" the patient would have ebola.
It comes after two Sierra Leone athletes tested at the Commonwealth Games were found to be clear of the virus.
Ebola is transmitted by direct contact with body fluids of a person who is infected. More than 1000 people have died and almost 2000 suspected, probable or confirmed cases have been recorded since the outbreak began.
Medical agency Médecins Sans Frontières has warned it could take six months to get the outbreak under control.
A spokesman for the World Health Organisation in Geneva, said beds were filling up faster than they could be provided.
The UN health agency warned the official counts of 1,069 dead and 1,975 infected may "vastly underestimate" the size of the outbreak.