The city’s anti-corruption and antitrust watchdogs on Thursday said they had arrested 20 people after cracking down on a syndicate which allegedly engaged in corruption and tender-rigging in relation to building maintenance.

In their first joint operation, the Independent Commission Against Corruption (ICAC) and the Competition Commission said they arrested 17 men and three women aged between 36 and 70 years old.

The arrestees included the mastermind and other important members of the syndicate such as engineering contractors, engineering consultants, middlemen, members of the Owners’ Corporation, and staff of property management firms.

Computers, mobile phones, as well as bidding documents in relation to the building maintenance projects were among the items seized.

The antitrust watchdog said it exercised compulsory powers when searching some 40 premises with court warrants to require the relevant parties to present documents and information, during which some members refused to do so.

Companies and persons involved were alleged to have engaged in bribery and anti-competitive activities, manipulating the tendering process for building maintenance projects, exaggerating contracts sums, and assisting associated contractors to obtain the contracts, violating the Competition Ordinance.

The projects covered two residential estates and residential-commercial composite buildings on Hong Kong Island, as well as four residential and industrial buildings in the New Territories, amounting to HK$180 million.

Some of the single projects involved suspected bribes of over HK$1 million.

While half of the renovation projects were yet to be awarded, works of the remaining projects started before the two bodies commenced their investigations.

The ICAC and Competition Commission said that further enforcement action would not be ruled out as the investigation was still ongoing.