The re-trial found Mr Pora guilty of the murder and rape of the Papatoetoe woman in 2000.
Mr Pora, now 36, is imprisoned in the Paremoremo prison in Auckland.
Crown Prosecutor Jonathan Krebs said he was confident Mr Pora's innocence could be proven.
"We have real concerns about the voracity of the confession Teina has maintained. It's a false confession. And there is a new body of science in which the phenomena of false confessions is explored and explained," he told Radio New Zealand today (Friday).
He said the evidence linked to Mr Pora was "false and thin and weak" and couldn't be relied upon.
Mr Krebs applied for the Royal Prerogative of Mercy through the Governor General. The matter has been referred to the justice minister, who will offer advice on whether the case should be reopened.