Medical worker conducts novel coronavirus nucleic acid detection at the Diagnostics Virology and Transformation Center of the Guangzhou KingMed Diagnostics Group Co Ltd in Guangzhou, south China's Guangdong province, Feb 18, 2020. (LIU DAWEI / XINHUA)

GUANGZHOU - South China's Guangzhou, capital of Guangdong province, reported one asymptomatic case of COVID-19, who is a worker at a designated quarantine hotel for inbound travelers, local health authorities said Friday.

The man tested negative for coronavirus on Oct 5 in a routine nucleic acid testing for hotel staff, but the result turned positive on Oct 15 in another round of regular tests

The 40-year-old man surnamed Wang works in the city's Xinyuan hotel in Huadu district, where overseas arrivals undergo concentrated quarantine. He used to live in the staff dormitory of the hotel, according to a statement released by the district's health bureau.

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The man tested negative for coronavirus on Oct 5 in a routine nucleic acid testing for hotel staff, but the result turned positive on Oct 15 in another round of regular tests.

Experts said the case may be linked to imported cases.

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Wang has been sent to a local hospital for medical observation, while 68 close contacts have been put under quarantine and sampled for nucleic acid testing after Huadu district launched an epidemiological investigation on Thursday. Among them, 66 people tested negative and the results of the remaining two are yet to be released.