A former New South Wales judge has warned that prosecutors are so hesitant to take on corruption cases they should not be relied upon by a federal integrity commission to take criminal proceedings to court.

The Coalition’s current proposal for an anti-corruption commission, released late last year, does not allow it to make findings of corrupt conduct. The government’s model would only be able to make findings of fact, which would then be referred to prosecutors to decide whether to push forward with criminal proceedings.

But former New South Wales independent commission against corruption (Icac) commissioner, David Ipp, said his experience of prosecutors was that they were too concerned about their end-of-year statistics to be relied upon to take corruption cases to court.

Ipp, who led Icac between 2009 to 2014 and presided over the investigation of corrupt former Labor politician Eddie Obeid, said corruption cases were often complex and most prosecutors had little experience in dealing with them. He said if a federal integrity body was not able to make findings of corrupt conduct, such conduct would not be properly exposed.

“Having spent several years at Icac, sending material to the DPP, and facing the DPP’s refusal to prosecute because there are one or two difficulties in the case … the DPP is very interested, in my opinion, in his end-of-year statistics, to show how many prosecutions were successful and only very few were unsuccessful,” Ipp said.

“There is a hesitancy in the DPP agencies throughout the country, by the nature of the job, to prosecute in cases which present any difficulty and in cases which involve areas in which they are not familiar.

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“They are reluctant to prosecute and we have had many cases in practice where the DPP, despite our beseeching of him to prosecute, has declined to do so. In those instances, had we not made corrupt conduct findings, the corruption would simply not have been exposed.”

Ipp and fellow former senior judge, Anthony Whealy, were appearing before a Senate inquiry into the crossbench and Greens’ models for an anti-corruption commission on Friday morning.

The pair sit on an independent committee of five former judges who have helped deliver a blueprint for an effective, well-resourced, and broadly-focused integrity commission.

The majority of the committee do not agree with Ipp’s view that a federal integrity commission should be able to make findings of corrupt conduct. The majority believe findings of fact should be referred to prosecutors.

But the former judges all clearly agree that the federal body should be able to hold a public hearing if it is deemed in the public interest. The government’s current model only allows public hearings for law enforcement corruption, not public sector corruption.

“No one who has seen the enormous power and consequences of public hearings in the Hayne royal commission and the McClellan commission involving paedophelia could argue that the private interests of private individuals outweighed the immeasurable public benefits that the public hearings of these commissions produced,” Ipp said.

Ipp and Whealy said the federal government’s proposed anti-corruption body falls “disastrously short” of what is required.

“We repeat that the government’s model falls disastrously short of providing an effective anti-corruption agency, and moreover an ineffective commission is worse than no commission at all,” Ipp said.

They said the commission’s independence was of prime significance, and oversight bodies should not be able to interfere with decisions to investigate matters or hold inquiries.

“Any such interference would destroy the independence of the proposed agency,” Ipp said.