Twenty-one people have been arrested in an operation targeting a triad-linked corruption syndicate accused of influencing renovation projects at two residential estates in Kwun Tong.

Among those apprehended last week were core members of the group, according to the Independent Commission Against Corruption (ICAC) on Friday.

Others detained were intermediaries, engineering consultants, contractors and members of housing estate owners' corporations.

Some are believed to have ties to triad societies.

In one of the projects, the ICAC said, a contractor is alleged to have bribed engineering consultants and members of an owners' corporation to secure a HK$33 million contract through intermediaries.

The other project, which is still in the preparatory stage, involved an intermediary suspected of collecting authorisation documents from homeowners "through corrupt practices", with the intent of controlling the owners' corporation to help acquire renovation work contracts in future.