Reece Kershaw, the commissioner of the Australian Federal Police, spoke at the National Press Club on 22 July. He was asked about his views on a federal anti-corruption commission. He had nothing to say, except that the federal police already had the capacity to investigate corruption, if such a matter were referred to them.

Kershaw would still be waiting for the Morrison government to refer government corruption arising from the “sports rorts” affair.

The AFP have an unimpressive record in dealing with federal politicians. There have been no convictions of a commonwealth minister in the performance of their duties since the AFP was formed in 1979. This is contrary to the experience in most states. Think of Queensland’s prosecuted and jailed ministers, or the New South Wales police, which recently pursued the state arts minister with excessive zeal (he was cleared of any wrongdoing).

Some might say the commonwealth is blessed with incorruptible politicians. But the main reason federal ministers have escaped scrutiny is the AFP’s reluctance to intervene in political matters. This unwillingness is heightened when, as now, the government has a slim majority. The AFP showed their disinclination when they failed to investigate the apparent fraud underlying claims by the federal energy minister, Angus Taylor, concerning Sydney city council’s overseas travel spending. Taylor has “unreservedly” apologised to Sydney lord mayor Clover Moore for relying on the falsified figures but has denied consistently that either he, or anyone in his office, altered the City of Sydney document to inflate travel expenditure.

AFP’s need for a referral is one reason the commonwealth needs an anti-corruption body. A police service that tries not to upset the government is no defender of democracy. Another reason is that corrupt activity is not always a crime.

The attorney general, Christian Porter, was wrong when he told the ABC on 3 March that integrity commissions only investigate “things which are written into statute as offences”. He was wrong when he said, “Neither the police nor integrity commissions investigate things that aren’t offences”. In common with other states, NSW legislation takes a broad view of corruption. For example, the partial exercise of official functions by a NSW public official, whether or not in NSW or Australia, is sufficient to lead to a finding of corruption.

Porter’s assumption that the sports grants affair involved no offences is also wrong. The responsible sports minister at the time, Senator Bridget McKenzie, provided evidence that her signed and dated advice to the Australian Sports Commission was altered without her knowledge. This was done when some applicants McKenzie had selected were deleted and substituted with others. Scott Morrison has sought to distance both himself and his office from the controversy, but evidence submitted to the Senate committee examining this matter identified specific changes that were made at the request of the prime minister’s office. If Porter thinks this is a matter of no moment, we have a very poor attorney general.

Then there is the possible offence of abuse of office under the Criminal Code Act. McKenzie claims that her selecting applicants for the $100m of available grants under the Sports Infrastructure Grants program was to ensure that grants were widely distributed throughout Australia. But evidence suggests that McKenzie’s office and Morrison’s office were more concerned with using the grants to obtain electoral advantage. The National Audit Office report into the sports grant program concluded that: “The Minister’s Office drew upon considerations other than those identified in the program guidelines, such as location of projects …”. If it can be shown that commonwealth public officials used their positions to dishonestly cause a benefit to another person or to dishonestly cause a detriment to another person, there is the possibility of the offence of abuse of office.

It is unlikely that the AFP or the attorney general will pursue these possibilities. It is also improbable that the Morrison government would allow any federal anti-corruption body to investigate these matters before the next election. So Porter and the possible principals in the matter, Morrison and McKenzie, can safely assume that the sports rorts will not be investigated by any law enforcement or anti-corruption body any time soon. In a submission to the Senate inquiry into allegations of political favouritism in handing out sports grants McKenzie has denied any wrongdoing.

One benefit of the sports rorts saga is that it shows an effective federal anti-corruption commission is urgently needed. Porter’s first effort to create such a body remains a failure. He would not allow such a body to examine corruption that was not a crime, nor would he permit an anti-corruption body to examine past matters. And there would be no public hearings for parliamentarians or their staff, notwithstanding that the courts have public hearings every day on allegations that are judged unproven.

In light of state governments’ efforts to curtail the work of their anti-corruption bodies, and the Morrison government’s lack of enthusiasm, a commonwealth body would need to be established with as much independence from government as possible. Thus, the appointment of the commissioner should be a matter for parliament, not the government. From time to time, NSW governments have shackled the state’s Independent Commission Against Corruption by appointing less than capable commissioners. The annual funding of such a body should also be determined by a statutory parliamentary oversight body. The absence of such a protection has enabled successive NSW governments to limit the work of the Icac. And where the commissioner thought it in the public interest, public hearings should be permitted.

If the commonwealth wanted an example of best practice, it might examine the legislation establishing the Integrity Commission in the Australian Capital Territory. The ACT Greens, with the Liberal and Labor members of a committee of the ACT legislature, successfully established a commission that would be an ideal model for the commonwealth.

• Tony Harris is a former NSW auditor general and senior commonwealth officer