National Party leader Don Brash has supported a call for an independent body to identify miscarriages of justice.
He was commenting on a report by retired High Court judge Sir Thomas Thorp, which said up to 20 people may be wrongly imprisoned in New Zealand.
Sir Thomas has called for an independent authority to be set up to identify miscarriages of justice.
The recommendation follows a two-year study of the nature and incidence of miscarriages of justice, and the way New Zealand and comparable countries deal with such claims.
Sir Thomas looked into the Peter Ellis Christchurch creche case for the Government.
Dr Brash and National MP Katherine Rich supported the call for a Royal Commission of Inquiry into the Ellis case in 2003, and attracted support from 11 law professors and two former Prime Ministers for the inquiry.
"It is cases like the Peter Ellis case that highlight the need for an independent body with the resources and authority to investigate possible miscarriages of justice," Dr Brash said.
"It is critical that the public have complete confidence in our legal system.
The Ellis case cast doubt in people's minds.
"An independent authority would take steps towards alleviating the public's concerns."
Sir Thomas said "up to a score" of New Zealand inmates might be wrongly jailed.
Analysis of 53 applications to the Justice Ministry claimed miscarriages of justice from 1995 to 2002, he revealed.
Of these, he classified:
* 26 per cent as "raising issues that clearly required careful investigation".
* 16 per cent were "plainly without merit".
* 58 per cent had "sufficient potential to require some further investigation".
Sir Thomas' report, titled Miscarriages of Justice, has been published by the Legal Research Foundation, a non-profit body associated with Auckland University's law faculty.
Counsel for Ellis, Judith Ablett Kerr, QC, said the proposal for an independent authority to look at possible miscarriages of justice looked extremely interesting.
"It's something I've been pushing for several years, not just in relation to the Ellis case."