The Independent Commission Against Corruption (ICAC) on Friday said it had arrested 49 people as part of its largest ever investigation involving the building maintenance sector.

The graft-buster said it suspects a gang paid bribes to secure maintenance work contracts worth a total of HK$500 million.

Those arrested include engineering consultants, contractors and suspected triad members.

Bryan Chong, the ICAC’s Assistant Director of Operations, said that in one case, a HK$1.5 million bribe is suspected to have been paid to property management staff for a HK$200 million maintenance contract at a housing estate in Islands District.

Chong said officers stepped in before eight of the 10 projects got underway, adding that their investigation has not been easy.

"We started off with limited information. Throughout the initial enquiry, we did a lot of investigative work, in order to establish that there was actually a big syndicate behind the scenes. I think the difficulties in this case would be how to professionally deal with the information that came to us, in particular with limited information at the initial stage," he said.

Chong called on homeowners to contact the ICAC if they find anything suspicious regarding the tendering process for building maintenance works.