The case has led to officials warning male Ebola survivors to refrain from having unprotected sex indefinitely.
Advice had earlier stated that men who survived Ebola should have protected sex for at least three months after displaying symptoms.
Investigations into other Ebola cases in West Africa look to be transmitted by sex, but this has not been confirmed.
Fewer than 10 such cases have been identified by the US-based Centers for Disease Control.
Ebola has killed almost 11,000 people in West African since December 2013, primarily in the states of Liberia, Guinea and Sierra Leone and more than 25,000 cases have been identified.
The most recent Ebola outbreak is the first to reach epidemic proportions; it is believed that poverty, poor healthcare systems and a delay in responding has led to failure to control the disease.
Ebola is now largely under control in Liberia and international organisations have scaled back their presence in the country.