The patient, an 18-year-old man, was undergoing quarantine at a hotel in Sai Ying Pun after flying in from the Netherlands.
He did not have any symptoms.
Meanwhile, the centre said it was investigating what it called a suspected “re-positive” coronavirus case involving a member of the Consulate General of Kazakhstan.
The 39-year-old man was infected in Kazakhstan in June.
He arrived in Hong Kong on Wednesday and tested preliminary positive for the virus. But a subsequent test was “uncertain”.
The man was sent to hospital for further checks.
Sources said he lives in Manhattan Heights in Kennedy Town.