Further research is needed to identify the specific source - whether animal or otherwise - of the coronavirus that is causing the Middle Eastern Respiratory Syndrome (MERS) in humans, the United Nations Food and Agriculture Organisation has said.
"It is not yet clear how people are becoming infected, or where the virus might come from," said Juan Lubroth, the organisation's chief veterinary officer in a statement.
"We do not have enough information to identify with certainty the virus' origin. Confirming the source and mechanisms of transmission and spread are key to developing ways to reduce the risks posed by this virus to humans or other countries."
The comments come after a study led by the National Institute for Public Health and the Environment of the Netherlands found antibodies for the MERS coronavirus in camel blood samples.
The study claimed people infected with the deadly virus that emerged in Saudi Arabia last year may have caught it from one-humped camels used in the region for meat, milk, transport and racing.
Scientists said they had found strong evidence it is widespread among dromedary camels in the Middle East.
The Middle East Respiratory Syndrome Coronavirus (MERS-CoV), which can cause coughing, fever and pneumonia, has been reported in people in the Gulf, France, Germany, Italy, Tunisia and Britain.
The World Health Organisation (WHO) says 46 people have died out of a total 94 confirmed cases, the majority in Saudi Arabia.
"These antibody findings indicate that the MERS virus, or a similar coronavirus, occurs in some camels and potentially other species," the statement said.
It added; "However, the only way to know with any certainty if the virus affecting humans is the same as the virus possibly affecting camels (or any other animal) is to isolate the virus in different species and compare them genetically."
The UN organisation urged countries to invest in efforts to better understand virus sources and mechanisms of transmission and spread, and said it is ready to support national and regional efforts to identify the source.
The Rome-based agency added that it is in close communication with national authorities as well as the World Health Organisation and the World Organisation for Animal Health (OIE) and is monitoring the situation closely.
Coronaviruses are a family of viruses that affect primarily birds and mammals.
Some strains cause mild disease, while a limited number are more harmful such as the Severe Acute Respiratory Syndrome (SARS).
The MERS coronavirus has been shown to cause acute respiratory illness in humans, but has not yet been shown to cause disease in animals.