Former lord mayor Robert Doyle has been found unfit to be interviewed about sexual harassment allegations during his time with Melbourne Health.

Victoria's Department of Health and Human Services gave Mr Doyle 10 days to respond to its request for him to attend an interview or undertake an independent medical evaluation to assess his ability to answer the claims.

The department has now released a statement which said senior independent investigator, Charles Scerri QC, was satisfied Mr Doyle is not medically fit to be interviewed about the claims.

"Mr Scerri said new medical evidence provided to him indicated it would not be safe for Mr Doyle to be questioned at this time," the statement said.

Mr Doyle is accused of groping a woman at a black-tie event in 2016 when he was chairman of Melbourne Health.

Victoria's Health Minister, Jill Hennessy, ordered an investigation by Charles Scerri QC, but he couldn't reach any final conclusions because Mr Doyle was too ill to respond to the claims.

In a report released last month, Mr Scerri said there was no reason to doubt the claims made by the woman, known as Carla.

The department said it had written to Mr Doyle on multiple occasions but was told each time the former lord mayor was "unable to participate" on medical advice.

The department said the investigation into the allegations is continuing and Mr Scerri is expected to receive a further detailed medical opinion in the coming days.

The complainant, a woman known as Carla, said earlier this year that she was "gutted" by the process surrounding her complaint and that she would "definitely not" report harassment again in future.

"I feel foolish… because I believed in the process," she said on ABC Radio Melbourne.

"I was told that there would be an outcome, that whilst Robert Doyle wasn't compelled to respond, that basically Charles Scerri would make a call."

In March, a separate investigation by Melbourne City Council into allegations of sexual misconduct towards a councillor and a former councillor made four adverse findings against the former lord mayor.