Alan Hall's miscarriage of justice: Wrongful murder conviction inquiry must unravel 'extremely troubling' issues

An investigator who helped overturn Alan Hall's wrongful conviction for murder says Hall would prefer an inquiry into the injustice be thorough rather than quick.

The Supreme Court quashed Hall's murder conviction, after evidence presented to a jury at his trial 36 years earlier was found to have been tampered with.

Now 60 years old, Hall spent 19 years in jail - and almost as long on parole - after Papakura man Arthur Easton was killed.

Alan Hall spent more than 35 years in jail or on parole for a crime he never committed. Photo / Greg Bowker

"It's a positive step that the Solicitor-General is looking at it," investigator Tim McKinnel said this afternoon.

"There remain many unanswered questions about what happened."

Lawyer Nicolette Levy QC is leading the inquiry which Solicitor-General Una Jagose announced earlier today.

McKinnel said the investigation did not seem to have powers of compulsion.

Alan Hall leaves the Supreme Court on Wednesday after his 1986 conviction for murder was finally quashed. Photo / Mark Mitchell

He said it would be a surprise if Levy's inquiry insisted people involved in the case come forward, so it would likely rely on goodwill and co-operation.

"There's a broader question around whether there's been criminal misconduct. I suppose that's a matter for police, and we're in the dark about what they are or aren't doing," McKinnel added.

"Our view is the issues that have emerged thus far are extremely troubling."

McKinnel said the investigation should examine not just the role of Crown lawyers, but everyone involved in the case.

It was crucial to ask how someone "can be so egregiously wrongly convicted for 36 years", he added.

McKinnel also helped overturn the wrongful rape and murder conviction of Teina Pora.

Pora spent 22 years in jail for crimes he never committed.

McKinnel said Hall, apart from being jailed for nearly two decades, was also tethered to very restrictive parole conditions for 17 years.

Private investigator Tim McKinnel says the investigation into Alan Hall's egregious miscarriage of justice must be thorough. Photo / Doug Sherring.

"From Alan's perspective, he would rather thorough than quick," McKinnel said when asked about desirable investigation timeframes.

"It should take as long as it needs to."

Attorney-General David Parker today said he supported the Solicitor-General's investigation into the case.

"It's a case where there appears to have been a miscarriage of justice," Parker said.

"And as a consequence, a New Zealander was imprisoned when he ought not to have been."

Teina Pora wrongly served 22 years in prison for a crime he never committed - the brutal 1992 murder of Susan Burdett. Photo / Michael Craig

Parker was asked what might happen if the investigation unearthed wrongdoing.

He said the Solicitor-General appointed an external barrister to go through Crown Law files and see what fault, if any, lay with Crown Law.

Justice Minister Kris Faafoi said legal processes had to be followed and he didn't want to prejudice the outcome of any investigation.

"There's obviously been a court ruling. Ministers of Justice don't comment on that."

Faafoi was asked about possible compensation for Hall.

"We'd have to get advice on that if that's a track that is traversed. Until that's a reality, there's not much I can say."

Asked if New Zealanders could have faith in the justice system after the outrageous miscarriage of justice, Faafoi did not directly answer.

"That's an issue for Crown Law," he replied.