The New Zealand government has rejected a report into a wrongful murder conviction prepared by an eminent Canadian judge, alleging it is rife with error and slanted in favour of the accused man.

The rejection is the latest event in a week-long public sparring match that has gripped the country. The report's author, retired Supreme Court of Canada judge Ian Binnie, and New Zealand Justice Minister Judith Collins have repeatedly slammed each other over motives and credibility.

The dispute had its genesis in 2011, when a previous New Zealand government asked Mr. Binnie for recommendations on compensation for David Bain, who was wrongly convicted in the high-profile 1995 murder of his parents, two sisters and brother, whom Mr. Bain said he found shot to death in the family home in Dunedin, N.Z.

Story continues below advertisement

Mr. Bain was behind bars for 13 years before he won a new trial. His second trial, in 2009, featured evidence of police tunnel vision, botched forensic testing and incest within the Bain family. Mr. Bain was acquitted.

Mr. Binnie delivered his report about three months ago. It was released on Thursday. He recommended compensation and said police made "egregious errors" that led to the conviction.

In a statement on Thursday, Ms. Collins said the report unfairly maligned police and prosecutors and considered inappropriate evidence. She also accused the former judge of being ignorant of her country's legal regime and producing a report that "lacked a robustness of reasoning used to justify its conclusions."

In a blistering retort, Mr. Binnie said that a New Zealand lawyer whom Ms. Collins asked to conduct a peer review of his work misunderstood the Bain case and the report. He said the review was undertaken purely to provide a rationale for rejecting it.

Mr. Binnie also mocked Ms. Collins for asking the country's solicitor-general to undertake a critique of his report. He questioned the independence of the solicitor-general's office in the matter, saying it had struggled for 17 years to uphold the case, which has proven to be a miscarriage of justice.

Mr. Binnie said it was "most improper" for Ms. Collins – whose government was his client – to denounce his work and then say he could not respond without violating solicitor-client privilege.

The Bain case has divided New Zealanders into two camps: those who believe Mr. Bain was persecuted by a myopic justice system and those who believe he pinned the murder spree on his dead father and got away with it.

Story continues below advertisement

Mike Hosking, host of New Zealand's highest-rated radio show, on Newstalk Z, said the murders and the legal wrangling that followed are the stuff of Hollywood scripts.

"It is our most controversial and significant case and remains, for many people, unresolved," Mr. Hosking said. "It is a classic whodunit. People remain divided and entrenched in their views."

Speaking at a University of Toronto criminology conference last month, Mr. Binnie was sarcastic about the way his assignment began.

"There were two words of advice," he said. "The first was that whatever I say isn't going to change anybody's mind. And the second was, I should deliver my report on the way to the airport – preferable throwing it back over the security barrier just before the plane left."

At the conference, Mr. Binnie described the family as "very introverted and reliant on one another, and somewhat weird."

He noted that no motive was ever furnished for Mr. Bain to have killed his family. In contrast, he said, evidence had showed that one of the sisters intended to confront her father, Robin, with allegations that he had been molesting her for years.