The government said on Saturday it had completed an overnight lockdown of 35-37 Nam Cheong Street in Sham Shui Po, and also tested people nearby. No positive cases were found.
They said they had verified that everyone affected by the exercise had undergone compulsory Covid tests.
They imposed the lockdown after a construction worker who lives there tested preliminary positive for Covid.
Health officials said they wanted to make contact with five households who didn't answer their door overnight.
About 50 people were tested during the exercise.