A think tank on Tuesday suggested the government set up a unit dedicated to helping owners' corporations, in particular those at old buildings, to protect homeowners from bid-rigging.

The call is among a raft of recommendations that the PoD Research Institute has made after launching a study into bid-rigging in view of the deadly Tai Po fire that happened in November.

Research director Ray Poon said bid-rigging often involved hidden agreements in which contractors would take turns to win a tender and split the income, causing homeowners to bear significant safety threats and financial losses.

"One thing that the dedicated unit could do is to set up a digitised purchasing system. So with this system, future tenders will have to submit to [scrutiny by] this particular unit instead of being vetted by the owners' corporation themselves," he said.

"And on this system, all the prices and the process will be analysed digitally with the help of AI, so that when there are any suspicious activities, the system could create an alert for both the enforcement unit and also owners."

The unit can also use a digital passport to record the tendering and maintenance activities of every building, Poon added.

Director Ronny Tong stressed that society as a whole had a duty to fight bid-rigging.

"I think the community itself, via communication and sharing of information, can also enable early detection of such behaviour," he said.

"I think that there is no shape or form as to exactly how this could be done. Rather, it is a concept which I think the community should embrace in order to come together to share information and to have a common goal of preventing bid-rigging to take place in Hong Kong."

The group also called for bid-rigging – which is currently a civil offence – to be criminalised by amending the Prevention of Bribery Ordinance to step up the deterrent effect.