Justice Minister Judith Collins is seeking more legal advice before making a recommendation to Cabinet on whether compensation should be paid to David Bain.
Mr Bain spent 13 years in jail for the 1994 murders of his parents and three siblings, before he was acquitted at a retrial in 2009.
He is seeking compensation for wrongful conviction and imprisonment.
Ms Collins has received a report on the claim from a retired Canadian Supreme Court judge, Justice Ian Binnie. When she received that advice, she indicated a decision might be made before Christmas.
On Monday, Prime Minister John Key said she had sought further advice and clarification from a Queen's Counsel on the report.
"She had some concerns, or at least issues, she wanted to flesh out a bit more before she took the next step. There'll be a lot of public interest in what happens here and I've said the Government needs to ensure that it's fair."
Mr Key says he expects an update from the minister next year.
Delay disappoints Bain lawyer
Mr Bain's lawyer, Michael Reed QC, is urging the Government to release the report.
He says he is disappointed by the delay and secrecy.
"The Government chose this man, not our man. They chose this man because of his credentials and because of his independence and his stature and he did a very thorough report over six months. We don't know what's in it but we've always said we would accept what's in it - win, lose or draw - and it's time the minister accepted it, win, lose or draw."