"There is a possibility that the patient may have contracted the SARS coronavirus," Xu Ruiheng, deputy director of the Guangdong centre for diseases prevention and control, said on Hong Kong cable television, citing results from viral gene sequencing.
A 32-year-old television worker is suspected to have contracted Severe Acute Respiratory Syndrome (SARS), sending ripples through a region that was severely affected by the mystery virus last year.
The WHO, which is working closely with Chinese authorities, said it could not confirm the finding, as details of the Guangdong tests had not been shared with the WHO.
Earlier this week, Guangdong health bureau spokesman Feng Shaoming said local tests showed the patient had been infected with SARS, but the health ministry said it wanted to carry out further tests.
The ministry's daily SARS report on Friday said the patient remained in stable condition.
Tests under way
The report on Hong Kong TV, and carried by the official Xinhua news agency, came while testing of samples from the patient were under way in two Hong Kong labs.
In Hong Kong, acting deputy director of health Regina Ching said medical experts had started conducting a battery of tests on the samples.
The WHO is confident that China's
raised level of alert will prevent
any major outbreak
"Most of the tests we have completed but some tests are still ongoing," she said.
"For the tests we have completed, we have already sent the results back to the World Health Organisation for their interpretation," she said.
It is likely the results will be passed to China's Ministry of Health before being made public by the WHO.
The ministry agreed to ship the samples overseas after repeated tests this week proved inconclusive.
"It's a confusing picture," WHO spokesman Roy Wadia said. "The availability of test results from the Hong Kong laboratories may help clear this up."
Whatever the outcome, the WHO said China's raised level of alert and resources spent on curbing the SARS virus will prevent any major outbreaks.
Even if a few cases, or clusters of cases, of SARS were to occur it would be possible to prevent massive spread, Julie Hall, SARS team leader of the WHO China office, said.
China was the country worst affected by the SARS outbreak last year, with 5327 people infected nationwide of which 349 died.
In Guangzhou, a three-man WHO team on Thursday held an eight-hour meeting with three Chinese health department officials to review what they had learned since the case came to light last Saturday.
"They basically went through their investigations so far and listed their observations," said Wadia.