The Supreme Court is considering whether to admit new evidence during a bid to overturn Peter Ellis' 13 remaining convictions for child sex offences.
Ellis died in September 2019, but his case is being heard posthumously.
The Crown submitted new evidence after a complaint was made to police in February 2019, but it was never put to Ellis.
The Supreme Court today heard arguments about whether to admit evidence from a new complainant, who says she was raped by Ellis as a child 10 years before the Civic Creche case.
Crown lawyer John Billington admitted the woman's complaint raised some red flags, but said the court must decide if the evidence was helpful in deciding the case.
He said the evidence hinged on memory.
"Given the nature of the case, is it evidence that this court considers would assist it in relation to the substantive issue that you have to hear in October."
The Supreme Court will hear a substantive appeal of Ellis' convictions in October.
A lawyer representing Ellis in his appeal, Rob Harrison, has argued it is unfair to admit new evidence that he never got a chance to hear.
Harrison said the complainant went to police in February 2019 but was told they would not pursue it because Ellis was terminally ill.
"There was ample opportunity for them to go and speak to Mr Ellis and put those allegations to him, my understanding is the file was then sent to Christchurch at that stage and again, people could have spoken to Mr Ellis."
Harrison said there were too many inconsistencies in the evidence about when the complainant identified Ellis as the perpetrator.
At one point the complainant claimed to have recognised Ellis in media coverage in the '90s but elsewhere said she only recognised him when watching a documentary on the creche case in 2007.