They confirmed on Monday the deaths from a blaze that tore through seven high-rise buildings in the northern district of Tai Po.
Police were still searching the scene as more than 30 other people remained unaccounted for.
Authorities said the fire appears to have started in protective netting around scaffolding put in place for renovation work.
A senior official on Monday said on-site inspections have found that some of the netting did not meet fire safety standards.
The official criticized the company involved in the repair work, saying it disrespected human lives for meager cost savings.
Investigative authorities have so far arrested more than 10 people, including senior officials of the company involved in the repair work.
Hong Kong media reported that a man was detained Saturday on suspicion of sedition after launching an online petition with four demands, including government accountability and the creation of an independent investigative committee to probe the fire.
National security police reportedly arrested a former district councilor and a volunteer on Sunday for allegedly attempting to incite sedition in relation to the blaze.
The Chinese government’s security agency in Hong Kong released a statement on Saturday, warning that people who use the disaster to conspire to disrupt Hong Kong will be severely punished under the Hong Kong national security law.
