The National Institute of Health (NIH) will need a couple of more days to determine whether a man in his forties, who was classified earlier as the nation's first probable case of severe acute respiratory syndrome (SARS), is a probable SARS patient or not.

The man was classified Monday as South Korea's first probable SARS case but the health authorities later said there is a reasonable possibility that the patient is not a SARS victim because he recovered considerably after antibiotic treatments which do not affect SARS patients.

The health agency, however, reversed its remarks Friday by saying there is no evidence he is infected with bacterial pneumonia instead of the deadly respiratory disease.

It added that the determination on whether he is a SARS patient or not will likely be made in one to two days.

The man was categorized as a probable case since he had exhibited the symptoms of SARS sufferers according to the World Health Organization, including a trip to a region where SARS cases were reported, a high fever, respiratory problems and pneumonia.