Justice Minister Andrew Little has echoed the research of recently deceased judge Sir Thomas Thorp, who said there may be as many as 20 innocent people in prison at any one time.
Mount, who worked with Thorp, said the inability for the CCRC to look at privileged information was a "significant deficiency" in the bill and would lead to innocent cases falling short.
Such information could include confessions from a person who is not accused of a crime to a lawyer, priest or journalist, or information about flawed evidence that is privileged because it was communicated between an expert and a lawyer.
Mount said that the chair of the equivalent review commission in the UK had told the UK justice committee: "You can be confident there are miscarriages of justice that have gone unremedied because of the lack of that power."
Being blocked from such information would render the CCRC weaker than similar institutes in England, Wales and Scotland, weaker than a private citizen on trial who can apply to a court for such information, and weaker than the Ombudsman, who can use public interest provisions in the Official Information Act.
An appropriate safeguard to ensure access is not abused would be the courts, Mount said.
"The court should have the power to be able to make an order requiring disclosure of confidential or privileged information to the CCRC where there are proper grounds to do so," Mount said.
Investigative journalist Mike White supported Mount, telling the committee that without the ability to ask the courts for access to privileged information, the CCRC would be "muted, undermined or even torpedoed".
White, who has covered several high-profile murder cases, echoed many other submitters in noting the difficulty of the current system to challenge convictions.
"Make no mistake, there are people right now in New Zealand jails who are innocent ... The reality is it just happens. It's a human system."
He noted some of the highest-profile cases of wrongful imprisonment including David Bain, Arthur Allan Thomas, Teina Pora and David Dougherty.
White said such cases typically needed a tireless campaigner, a lawyer who cared enough for the case to work for free, family support, and financial means that empty retirement savings or see the house remortgaged.
Several submitters said the CCRC was an independent body and an improvement on the Royal Prerogative, which was described as the justice system investigating itself.
Nigel Hampton QC, appearing for the NZ Public Interest project, said a CCRC might draw out more innocent people who have been wrongfully convicted of lower-level crimes.
The CCRC would not be able to look at cases where the accused has died, but Hampton said this ability should remain for exceptional cases.
"Peter Ellis comes to mind ... an extraordinary miscarriage of justice - I say extraordinary because in my view the problem with Ellis is that ... he's been convicted (he claims) for crimes that never existed.
"If he were to die a convicted man, surely there should be vehicle available to have that sort of possibility referred to a commission such as this."
The Wellington Howard League and the Human Rights Commission told the committee that the CCRC should be able to look at issues such as institutional racism in the justice system, or at least direct Parliament to look at them.
