The Prime Minister says a fresh review of David Bain's bid for compensation is still one option being considered.
The Cabinet was briefed on the case by Justice Minister Judith Collins on Wednesday.
Mr Bain spent 13 years in prison and found not guilty in a retrial in 2009 of murdering five members of his family at their Dunedin home in June 2004.
A government-commissioned report by retired Canadian judge Ian Binnie found that Mr Bain was probably innocent, and should be paid compensation.
But a peer review by Robert Fisher, QC, found significant errors in that report.
Ms Collins has said Justice Binnie's report is fundamentally flawed and outside its terms of reference.
At the end of last year, the minister indicated that a that fresh review may be carried out and Mr Key said on Wednesday that remained an option.
"Robert Fisher, QC, didn't complete his report. He completed part one of his report, which was the critiquing of Binnie's assessment of the situation.
"There's other work that he could do or another person could do either domestically or offshore."
Mr Key says the Cabinet is likely to discuss the case again in February.