An independent investigation found six cases in which Mr Dragicevich's behaviour as head of the infrastructure and environmental services department fitted the council's definition of bullying.
The council subsequently held an internal investigation into other complaints made against Mr Dragicevich, including allegations that he blacklisted contractors and bent council rules and procedures.
The two investigations followed a joint complaint by four IES managers about the behaviour and management of the department under Mr Dragicevich.
Mr Brookbanks told the Herald that following the internal investigation, the council took legal advice and "some things" needed to be done as a consequence.
"One or two things were brought to John's attention and those matters were taken in hand and resolved ... That is all I'm prepared to say," he said.
Mr Brookbanks said there was no evidence that Mr Dragicevich had blacklisted contractors.
The council provided the managers with a copy of the independent investigation, but nothing formal about the outcome of the council's investigation.
In an email to Mr Brookbanks on March 30, one of the managers complained about the lack of action: "I have made a total of 16 written complaints against John Dragicevich ... and note that only two of those complaints have been investigated."
The email was sent after the release of the independent investigation by employment lawyer Penny Swarbrick, which found Mr Dragicevich had bullied six staff under the terms of the council's harassment policy.
This led the council to take "serious disciplinary action" against Mr Dragicevich, who kept his job.
The council is paying $300,000 in confidential settlements to two of the managers who resigned after the report came out in March.
Doug Low, a founding director of Morrison Low, said he was not aware that the company had allegedly been blacklisted.
Mr Low - who it was alleged Mr Dragicevich had issues with - said his company had had no dealings with Mr Dragicevich "for almost forever".
The company has been used by other branches of the council on the Auckland Plan - the city's long-term blueprint.
AECOM New Zealand managing director Dean Kimpton said the company provided a range of services to the council, including a number of on-going commissions to the IES department.
Mr Kimpton would not say if anyone at AECOM was aware of instructions from Mr Dragicevich not to award work to the company.
Mr Taylor, who was Auckland City Council chief executive from 1996 to 2005, said allegations of being blacklisted by Mr Dragicevich were news to him. "I always thought I got along pretty well with him [Mr Dragicevich]," he said.
Earl Shaver, who it was alleged was disliked by Mr Dragicevich because he had worked for the former Auckland Regional Council, declined to comment.