Multiple alleged victims have approached the investigation with claims of inappropriate behaviour relating to Cr Doyle's time as a school teacher, opposition leader and chairman of Melbourne Health. The exact number is unknown.

The Age is aware of at least three people who have contacted the investigation with allegations of inappropriate behaviour or sexual harassment but decided not to lodge official complaints. They say they are concerned about being identified, particularly if the matter were to reach court.

At least one person told The Age negative media coverage of former councillor Tessa Sullivan's harassment allegations meant they feared being "publicly vilified" if they were identified. They said this would damage their professional future.

Cr Doyle is fighting for his political life after the Minister for Health, Jill Hennessy, last week ordered a second independent investigation into allegations of sexual harassment at a Melbourne Health event.

At least four women have made sexual harassment allegations against the lord mayor. Former councillor Tessa Sullivan resigned in December after making explosive allegations that Cr Doyle had harassed and indecently assaulted her. And councillor Cathy Oke has told investigators that Cr Doyle had tried to kiss her, and clutched her thigh under a table in a separate incident.

The Age revealed that a third woman had made an official complaint about Cr Doyle repeatedly touching her leg at a Melbourne Health gala dinner.

And a fourth woman, Melbourne photographer Dianne Mallas, has told The Australian Cr Doyle touched her inner thigh and brushed against her breasts in 1997, during two meetings in his electorate office while he was the state member for Malvern.

Cr Doyle has denied all allegations, including the most recent allegations from Ms Mallas, and vowed to clear his name.

On Monday the lawyer acting for Cr Doyle, Nick Ruskin, a partner at K&L Gates, said: "The continuing attempts to diminish the lord mayor's reputation by publication of stories where no formal complaint has been made and he is asked to respond to sparse allegations without provision of any names is grossly unfair."

Ms Mallas says she felt "very conflicted" about revealing her identity after approaching the council's independent investigation. She was concerned that people would ask why she didn't report it at the time.

"It's important to understand that 20 years ago it was not so easy for a female to come forward," she said.

"As disappointed as I was that it occurred, I also recognised that I was quite young and vulnerable, it would be better to just move on."

But society had changed, Ms Mallas said: "I think it's time as a collective for women to come forward."

Josh Bornstein, the national head of employment law at Maurice Blackburn, says alleged victims are often concerned they will be disadvantaged in future employment if they are publicly identified as blowing the whistle on sexual harassment.

"To a certain extent that's right, and that's very unfortunate," Mr Bornstein said.

"Certainly the perception is strong in many people they will be blacklisted."

Speaking generally, Mr Bornstein said most of the clients he had represented preferred confidential settlements without public exposure.

The recent global focus on sexual misconduct had emboldened women, he said. Former clients who had signed confidentiality agreements in the past had been in touch with Mr Bornstein to see if they were now able to speak publicly.

(Mr Bornstein was approached by one of Cr Doyle's alleged victims but is not representing any of those in the investigation.)

Ms Sullivan has threatened to sue the Herald Sun for recent articles - including a front-page story with a photo of her in a bikini - with her lawyers stating they perpetuate a culture of "victim blaming" and "discrediting women by the way they present themselves".

A second article in the Herald Sun wrote of a "strange twist" in the Town Hall saga because Ms Sullivan changed her surname to Doyle a decade ago, but did not mention Ms Sullivan's mother hails from a long line of Doyles, a fact later reported in the Australian Financial Review.

On Monday afternoon Ms Sullivan lodged complaints about the Herald Sun's coverage with the Press Council, the Australian Human Rights Commission and the Victorian Equality Opportunity and Human Rights Commission.

The Melbourne City Council investigation's report is likely to be released next month.

Typically, a report of this nature would be presented to councillors by the chief executive officer for consideration, and include a right of reply. Councillors would have the option to cast a vote of no confidence in the alleged perpetrator.

The Minister for Local Government, Marlene Kairouz, can request the Governor and members of the parliamentary executive stand down a councillor while an application of serious misconduct or gross misconduct is assessed.

The Councillor Conduct Panel and Victorian Civil and Administrative Tribunal are responsible for assessing applications of serious or gross misconduct, respectively.

If a panel makes a finding of serious misconduct against a councillor, it may suspend the councillor from office for up to six months

If VCAT makes a finding of gross misconduct against a councillor, it may order the councillor to be disqualified for up to eight years.

Cassandra Collier, a senior associate from Minter Ellison working on the council investigation, said investigators were not able to comment on any aspect of the investigation, including the scope or reporting process, in order to protect the integrity of the investigation and the participants.