Former Victorian ombudsman Deborah Glass said ministerial staff remain unaccountable as she pointed to numerous examples of misconduct that failed to reach a high legislative threshold of criminal corruption.
One investigation into the state Labor Party found it misused $400,000 of taxpayer funds to pay for political campaigning at the 2014 election and included the sign off of more than 20 Labor MPs.
"The scheme was an artifice and it was wrong ... but I did not conclude that it was criminal," she told an anti-corruption commission conference in Melbourne on Tuesday.
"In short, nothing happened to anyone."
A second scandal in 2020 that involving branch stacking activity allegedly carried out by staffers doing factional work on the public purse spurred some reform, Ms Glass said.
"The investigation found evidence of widespread misconduct, including the misuse of public funds for political purposes and what we described as a catalogue of unethical behaviour," she said.
"But once again, it did not reach the criminal threshold which defines corruption in Victoria."
But the reform from the 2020 scandal, the creation of the Parliamentary Workplace Standards and Integrity Commission, still didn't adequately address oversight of ministerial staff, she said.
"In my view, we should recognise that the convention of ministerial responsibility is unenforceable and all too often ignored ...far better to ensure that the staff themselves are accountable for their conduct and subject to some form of independent oversight," she said.
"Too often, it seems, there have been no consequences when bad behaviour is exposed, be it of politicians or their advisers.
"But there are always consequences on public confidence, on the public purse, on trust in governance, who ignore them at their peril."
Operation Daintree which found ministerial advisers improperly influenced the award of a $1.2 million contract also didn't make findings of corruption "again, noting the high threshold required to do so".
"We found evidence which raised a suspicion of corrupt conduct by the then-premier and two successive ministers for health," Ms Glass said.
It also found a range of concerning conduct including a breach of public duties and ethical obligations of ministers and their advisers, she added.
This is what came to be known as grey or soft corruption in which decisions are made and rules are bent or broken for the benefit of the decision-makers' friends, political organisations, or networks.
"While grey corruption does not necessarily amount to criminal conduct, its effect on public confidence in democracy and its institutions is deeply damaging," Ms Glass concluded.
