Under pressure to act in the wake of the Independent Commission Against Corruption's inquiry into the firm Australian Water Holdings – and the lobbyists circling it and the government – Baird unveiled what he termed "tough new rules" for the sector.

The most dramatic change in the package, though, was not directly related to the lobbying industry.

It was the move to give ICAC the power to investigate and make findings in relation to breaches of the ministerial code of conduct.

The change was a recommendation of the ICAC following its report into the actions of former Labor ministers Eddie Obeid and Ian Macdonald in relation to a mining tenement issued over the Obeid​ family's farm at Mount Penny in the Bylong Valley. Both were found by ICAC to have acted corruptly.

The change meant that ministers who commit a "substantial" breach of their code of conduct may be found corrupt by ICAC.

While it clearly wasn't the issue that drove ICAC's recommendation for the change, one significant effect was that it put real weight behind the rules for ministers who take often high-paying and prestigious jobs after leaving politics.

The code of conduct states that a minister who is considering a job offer while in office – or within 18 months of leaving office – that relates to their last portfolio area must first seek ethical advice.

The advice is supplied by the parliamentary ethics adviser. The rules agreed to by the parliament state that when the adviser becomes aware that the former minister has accepted the job the parliament is informed and the advice is usually tabled.

The code says the rules are designed "to avoid a perception" that a minister or former minister "is or was influenced by the prospect of the employment or engagement" or that the minister "might make improper use of confidential information to which he or she has or had access while in office."

It seems like a reasonable system. But the case of the former deputy premier Andrew Stoner has exposed a problem.

When Fairfax Media began seeking information about Stoner's new job as a senior adviser to investment bank Moelis – a job that related to his former role as trade and investment minister – a loophole quickly became apparent.

The parliamentary ethics adviser – currently former clerk of the parliaments John Evans – is sworn to secrecy about whether or not he has even been approached for advice by a current or former minister – or any MP for that matter.

It meant that he was unable to confirm if Stoner had sought the advice as required by the ministerial code of conduct.

Even more absurdly, it appears that Premier Mike Baird was unable to find out from Evans either.

In fact, only Stoner himself could make the fact public either himself or by allowing Evans to do so.

There appears to be no time limit within which the adviser must be told of a job acceptance so it could go unnoticed indefinitely.

A referral to ICAC would not be guaranteed to shed any light on the matter, either.

Obviously if it moves to a public inquiry, the facts become known. But if not, there is a real possibility the public remains in the dark, given ICAC's propensity for not revealing publicly when and why it does not decide to investigate a matter.

The case of Stoner's post-ministerial employment shows why the parliamentary ethics adviser's role needs to be rethought.

Yes, MPs and ministers who may be considering quitting politics and taking a new job deserve some degree of confidentiality. After all, it would be unworkable if it became known every time they were considering taking a job.

But once the job is taken, scrutiny should be applied.

At the very least the parliamentary ethics adviser should be able to confirm whether or not a former minister has abided by the rules.

After all, they are using the privilege of the experience of public office to pave the way for a private sector career.