Only a third of the 260 poultry stalls at 64 retail markets have met the hygiene requirements for the resumption of live chicken sales on Wednesday.
Officers warned they could break into stalls where the operators could not be contacted to do clean-up work if needed.
Under the rules, all poultry stalls in a market will have to close unless all stalls meet the requirements.
Director of Food and Environmental Hygiene Cheuk Wing-hing said 48 hours' notice had been served yesterday to hawkers who government inspectors had failed to contact.
Mr Cheuk said they were empowered by the law to get into such premises to do clean-up work. They did not want those who had cleaned their stalls and passed an inspection to be unable to do business.
The sales ban was imposed after the H5N1 virus were detected in environmental swabs taken from four local retail markets early this month.
