The World Health Organization says it appears likely a new coronavirus can be passed between people in close contact.
The novel coronavirus (NCoV) is known to cause pneumonia and sometimes kidney failure.
The World Health Organisation (WHO) said different clusters in multiple countries are increasingly supporting the hypothesis the virus can transmit from person to person when there is close contact.
Since 2012, there have been 33 confirmed cases across Europe and the Middle East, with 18 deaths, according to a recent WHO update.
Cases have been detected in Saudi Arabia and Jordan and have spread to Germany, the UK and France.
The French health ministry has confirmed a second man had contracted the virus in a possible case of human-to-human transmission, while health officials in Saudi Arabia say two more people are reported to have died from the virus.
Coronavirus is known to cause respiratory infections in both humans and animals.
But it is not yet clear whether it is a mutation of an existing virus or an infection in animals that has made the jump to humans.