Police Commissioner Joe Chow said on Wednesday that government departments have been working hard to remove remnants of scaffolding at fire-ravaged Wang Fuk Court so residents can enter areas deemed safe as soon as possible.

At a press conference, the police chief said an inter-departmental probe has yet to determine the cause of fire that claimed 168 lives, but officers have been trying hard to speed up their investigation.

Chow said he hopes survivors can enter the blocks soon.

"Colleagues from other government departments have been working hard to hopefully remove all the remaining scaffolding so that it's safe," he said.

"But the removal doesn't mean people can enter the blocks immediately - relevant departments have to look at the building structure. They'll keep inspecting, so hopefully not long from now they can complete such work for residents to return home."

Deputy Police Commissioner for National Security Andrew Kan said three people have been prosecuted so far on sedition-related offences in relation to the blaze.

Kan also dismissed claims on social media that people were prevented from making online comments about the disaster.

He said everyone knows that Hong Kong has free speech and freedom of the press and if anyone was to point the finger at the police this would amount to a smear campaign against the force.

Meanwhile, Chow said there is no timeline as to when the police will adopt facial recognition technology for its public surveillance camera network, but he hopes this will be sooner rather than later.

The government had said that by 2028, some 60,000 CCTV cameras will be installed across Hong Kong under the "SmartView" system for crime prevention.

"We don't have a hard and fast rule or the fixed timeline. We are working on it," the commissioner said.

"That depends on a lot of [factors] like the technology, whether it's mature, whether we are ready for that, and also for the legal regime that we need to examine and to make sure that they are all in accordance with the law."

Chow stressed that the police attach importance to people's privacy and that the use of such technology complies with the law.