The Court of Criminal Appeal has certified that the former nun Nora Wall, who was wrongly convicted of rape, has been the victim of a miscarriage of justice.
Mr Justice Nicholas Kearns said the court was satisfied that newly discovered facts showed that there had been a miscarriage in her case.
Earlier, it was revealed that a young woman was lying when she gave an eyewitness account under oath in 1999 of seeing Ms Wall rape a 10-year-old girl.
Patricia Phelan from Kilkenny made a new statement to gardaí in 2001, saying she had not seen this.
Ms Phelan, 32, claims that in 1996 a friend of hers told her she had been raped by Paul McCabe, and that Ms Wall, then a Mercy nun, had held her down.
This woman had already made a complaint to gardaí and asked Ms Phelan would she make a statement to gardaí if asked.
Ms Phelan did make a statement, claiming she had seen the rape. She went to the Central Criminal Court and gave evidence at Ms Wall's trial that she had witnessed these events. Her evidence was crucial in corroborating the complainant's account.
But she now says she never actually saw this. She says she knew when she was giving her evidence that what she was doing was wrong and against the law, but she just wanted to get back at Ms Wall, who, it is alleged, physically abused her.