The development has raised fears of a resurgence of the illness that killed hundreds around the globe.
A government statement issued late on Thursday said the patients had undergone preliminary testing and the results showed none of them was SARS-positive.
"At this point, no laboratory test has shown any positive result to SARS," the statement said.
But microbiologist Guan Yi said it would take up to two days for conclusive results on the tests.
"The one-day tests are not really reliable," said Guan, a SARS expert from the University of Hong Kong.
A government spokeswoman said earlier all the patients had respiratory problems such as fever and coughs but they were in stable condition and under observation.
The suspected cases come about one month after the World Health Organisation (WHO) declared Hong Kong free of Severe Acute Respiratory Syndrome.
The city is just beginning to recover from the disease, which killed about 300 people and ravaged Hong Kong's economy.
If the tests are positive, it would be a major blow to Hong Kong and its government, which has faced massive protests over its handling of the earlier SARS outbreak.
The illness first surfaced in southern China late last year and was spread around the world by air travellers.
The illness, which slashed global air travel, infected more than 8,000 people and killed more than 800 of them.
The disease spread to Hong Kong in March and raced through one of the world's most densely populated cities.