Justice Minister Judith Collins is warning that court action regarding compensation for David Bain will only delay his case still further.
Mr Bain is seeking a judicial review of the minister's actions over a report she received from a Canadian judge suggesting Mr Bain should be paid compensation.
Ms Collins said the report was flawed and ordered a peer review of it by a New Zealand Queen's Counsel.
Mr Bain spent 13 years in prison but was found not guilty in a retrial in 2009 of murdering five members of his family at their Dunedin home in June 1994.
In a statement, Ms Collins says she has taken steps to ensure Mr Bain's application for compensation is fair and proper.
On Wednesday, Mr Bain filed a claim in the Auckland High Court, saying the minister breached his right to natural justice, breached the Bill of Rights, acted in bad faith, abused her power and acted in a biased, unreasonable and pre-determined manner.
A supporter of Mr Bain, Joe Karam, told Radio New Zealand's Morning Report programme Ms Collins is entitled to have the report peer reviewed but has done so secretly and has excluded input from the Bain team.
"Everything (Ms Collins) has done since the day Binnie's report was filed with her has been done deliberately but with her choice deliberately excluding Bain from the process," he said.
"It's lucky there's no gallows in New Zealand otherwise David wouldn't be around to apply for compensation."