An infectious disease expert on Thursday called on the government to stop recognising rapid test results, after the city saw a jump in cases reported through its self-test results system.
Wilson Lam from the Hong Kong Society for Infectious Diseases said he suspected some residents might have submitted results from months earlier.
"False positive results from rapid tests are rare," he said during an RTHK programme.
"I won't be surprised that people have done this for the vaccine pass requirements, as I understand that there've recently been more inquiries about how to meet these requirements as soon as possible."
Lam suggested that the authorities should only recognise cases that have been confirmed through PCR tests.
"Currently the daily case number is in the hundreds and Hong Kong certainly has the capacity to do it," he said, adding that PCR tests can help health officials keep a closer eye on Covid variants.
Lam's remarks came a day after Hong Kong saw its daily caseload jump by more than 100 to 505.
Health authorities said they noticed a surge in the number of people testing positive through rapid tests, while their PCR tests came back negative.
Officials added they are currently trying to verify all reported positive rapid test results with PCR tests.