"I remain troubled by a number of these cases. Though I do not criticise those involved in the process at all, I think there is merit in reinforcing the independence of the advice from the Ministry of Justice and moving the decision making to a separate independent body,'' Mr Power said.
Mr Ellis said he hoped new Justice Minister Judith Collins would act on Mr Power's recommendation, noting she had signed a petition in support in 2005.
Criminal Bar Association president Tony Bouchier said a criminal case review commission, like that in Britain, would have benefits over the pardon system.
"I think that a criminal case review commission would be superior to anything we've got at the moment because they would be a specialist commission,'' he told Radio New Zealand.
"Their independence would be the first thing, and the second things would be their expertise - the expertise they could apply to criminal cases in trying to dog down and get to the truth of the matter.''
Mr Ellis' lawyer, Judith Ablett-Kerr QC, said a truly independent body with the proper funding and skills could filter out unsuitable cases and refer those with merit to the Court of Appeal if justified.
She said the pardon process took too long, was expensive and relied on defence lawyers doing the work.
Mr Ellis has also called for a commission of inquiry into his case, which he said came at a time of worldwide mass hysteria over child abuse in creches.
But an inquiry has been ruled out while he can still take his case to the Privy Council in Britain - an option Mr Ellis has ruled out due to the cost.