A project manager at the troubled Darebin Council took cash, gifts and other benefits from a road contractor while awarding the firm more than $16 million in work, the state’s corruption watchdog has found.

The case, and another graft investigation into the City of Ballarat, have prompted the Independent Broad-Based Anti-Corruption Commission to warn that corrupt council officers can cash in when there are gaps in local government procedure and policies.

IBAC Commissioner Robert Redlich, QC, published a special report on Monday, saying allegations of corruption around council procurement operations were a “recurring feature” of complaints to his agency and its interstate counterparts.

The commission found that over a period up to 2014 a project manager at Darebin, in Melbourne’s inner-north, awarded millions in road contracts to a firm that was supplying him cash and gifts.

The benefits included alcohol, Grand Prix tickets and building work to the project manager’s house and that of his father.