A microbiology expert on Sunday said it's not necessary to quarantine all residents living at the Tai Po public housing block where three confirmed coronavirus patients live.
Yuen Kwok-yung from the University of Hong Kong, who inspected Heng Tai House at the Fu Heng Estate on Saturday night, said it's sufficient to only evacuate people from the top six floors.
The infected residents live on the 32nd and 34th floors of the 34-floor building. The latest patient, a 59-year-old man, lives on the 34th floor, two floors above a couple who got infected following a trip to Egypt earlier this month.
They all live at units ending with number 13. The man did not know the couple personally.
Yuen said it's likely that a plumbing air vent pipe - which removes gases and odours - near the roof, may be spreading the virus.
Meanwhile, some families have moved out of the estate voluntarily. A family of five was seen leaving with some of their their belongings on Sunday morning.
The family, which lives on one of the higher floors, said they were worried about the virus spreading in the block.
Outside the building, cleaners on Sunday morning used bleach to disinfect the surrounding area.
Some residents expressed doubts over a government claim that there is no problem with the design of sewage pipes in the building, saying there were sewage smells coming from the toilet whenever they flushed.