Peter Ellis, a convicted paedophile, could be given another chance to clear his name following a new Court of Appeal ruling which hits expert evidence given by psychologists.
The appeal court judgement, released on Christmas Eve, will force psychologists to be more specific about the signs of child abuse - and could affect hundreds of child sex abuse cases.
The latest issue of NZ Lawyer reports the case could give Peter Ellis, convicted of abuses at the Christchurch Civic Crèche more than 10 years ago, a fresh chance to clear his name.
She said if the recent appeal court ruling had applied to Ellis' case, evidence by the prosecution's expert witness Dr Karen Zelas would have been considered irrelevant.
This recent ruling looked at whether the evidence of a registered psychologist called at trial complied with section 23G of the Evidence Act, which governs the admissibility of expert evidence in child sexual abuse cases. It allows expert evidence on whether a complainant's behaviour was consistent or inconsistent with a sexually abused child of similar age.
The recent judgement found the expert must go further, discussing how consistent it is and also whether it was consistent with other factors.
Bernard Robertson, co-author of Interpreting Evidence : Evaluating Forensic Science in the Courtroom, told NZ Lawyer the judgement placed more responsibility on experts to describe how likely abuse was when discussing complainant behaviour.
"Cases such as these should be the subject of the Governor-General's reference to the Court of Appeal because they're miscarriages of justice by which hundreds of people have gone to jail," Mr Robertson said.
Ellis was convicted in 1993 of abusing seven children in his care between 1986 and 1991. He was freed in 2000 after serving two-thirds of a 10-year sentence.
It is believed that police investigation took place after claims a child from the crèche told his father he "hated Peter's black penis".
This prompted other parents to question their children about whether they had been molested.
The Ellis conviction sparked debate over the techniques involved in questioning very young children about such crimes.