Justice Minister Judith Collins is seeking advice on whether to hold an independent inquiry into the Teina Pora case.
Pora was convicted in 1994 of the rape and murder of Susan Burdett in her home. He was convicted again in a retrial in 2000; however new expert evidence suggests he may have been convicted on a false confession.
An increasing number of experts and some former senior police believe he is innocent.
A spokeswoman for Ms Collins said the justice minister had previously refused to comment on the case because it was potentially subject to judicial proceedings as Pora's lawyer, Jonathan Krebs, was considering seeking leave to appeal the case to the Privy Council.
However, Ms Collins said she was now seeking advice from officials after hearing Mr Krebs would prefer an inquiry be held before taking it to that point.
Mr Krebs welcomed the opportunity to discuss the possibility of an inquiry with her.
"I have said if the minister, with the greatest of respect, thought it was appropriate to have a discussion with me about the nature of our case ... then I'd be more than happy to engage in those discussions on a completely confidential basis before we file the Privy Council leave application."
However, Mr Krebs said he didn't want Pora to become a political football.
"I mean he's been in custody now for more than 20 years and if it's ultimately demonstrated that the conviction was wrong and then it's further demonstrated that he was in fact innocent ... then this will probably be the most serious injustice in recent times anyway."
All he wanted was for Pora's alleged wrongful imprisonment to be addressed.
"It's a question of which will be the quickest route to that course. If I could be given some sort of an assurance that I could talk to Teina and say 'hey, let's hold off on your appeal, let's appear instead in front of some sort of inquiry', then I think Teina would probably go along with that."
However, if Ms Collins thought the Privy Council was a more appropriate avenue for hearing Pora's appeal, "then that of course is the way it must be", Mr Krebs said.
He said he was donating his time pro bono because he believed passionately in Pora's cause. Philanthropists had suggested they were prepared to donate funds to help with the appeal process and their assistance was welcomed, Mr Krebs said. "I'm convinced that we have an extremely strong case."
Malcolm Rewa was convicted in 1998 of raping Ms Burdett after he was linked to semen from the scene. Two juries could not reach a decision about whether he murdered her. Rewa is serving preventive detention for solo attacks on 25 women.
TV3's 3rd Degree last week revealed that police believed Burdett's attacker was a serial rapist before Pora was put on trial but did not disclose this to his lawyers.
- additional reporting Claire Trevett