A serum which is made from the blood of Ebola survivors is reportedly being offered on the black market in West Africa as a ‘treatment’ for the disease, Daily Mail reports.

Health experts have raised an alarm over the unapproved serums saying that they could contain other harmful infections.

The World Health Organization (WHO) is said to have vowed to work in collaboration with governments of the affected nations to stamp out the illicit trade.

Bloomberg News reports that the 'convalescent serum' is made from survivors' blood, which contains antibodies that could help fight the virus.

However, the Director-General of the WHO, Margaret Chan, said:

‘There is a danger that such serums could contain other infections and wouldn’t be administered properly.'

Ebola has killed over 2000 people this year and infected over 4000 in West Africa. There is no cure for the disease.