I had a suicide of a similar time period in NSW and the death certificate stated
death by hanging, suicide, finding at enquiry held at ... on .... (it was the day after the death) by .... (he was a J.P. ) I haven't gone looking for any further information as it related to a rather sad family story & I doubt the inquiry would have yielded any more detail.
I assume Victoria certifcates are similar & this should give you the date to search for the inquest (presumably at the archives).
Trish