The government is being urged to dump a law as a stumbling block to any prosecutions over the CTV building collapse.
Police last week decided not to bring manslaughter charges against two engineers who designed the CTV building, which collapsed in the 2011 Christchurch earthquake killing 115 people.
Under section 162 of the Crimes Act no-one can be held criminally responsible for a death that occurs more than a year and day after an act that contributed to the person dying.
Deputy Solicitor-General Brendan Horsley, in his review of the CTV investigation, said the law was likely to be a "complete bar" to prosecuting engineers Alan Reay and David Harding for manslaughter, because they designed the building in the mid-1980s and it collapsed in 2011.
He called section 162 an "anomalous anachronism".
"The present case [CTV] illustrates why reform is needed," Mr Horsley wrote.
In 1991 the government was advised by the Crimes Consultative Committee to ditch the "year and a day" law.
Other countries have dropped it, including the UK which abolished the rule in a 1996 Reform Act.
Chris Gallavin, law professor and deputy pro vice-chancellor at Massey University said most people in New Zealand would say the year and a day law "is an absolute arse, and they would be right".
"There's a very strong argument that section 162 was the deciding factor not to bring a prosecution here, so it's almost inescapable that section 162 has caused a travesty of justice in this case."
The police and Crown Solicitor wanted to prosecute in the CTV case but there were other factors weighing against it, as well as the length of time between the design and collapse, and police concluded there was insufficient evidence to provide a "reasonable prospect of conviction in court".
The previous government was looking at reforming the legislation.
Amy Adams, justice minister in the National government, said she had revived efforts to do so in June this year, and had asked officials to bring back final policy decisions and a draft Bill for Cabinet approval, but the election intervened.
Justice Minister Andrew Little has not committed to the law's repeal, but is casting the net wide.
"I've seen only one piece of advice on it. I'm waiting for official advice on that and the other questions I've raised about the gaps in the law," he said.
"I don't want anybody to think that is the only thing that needs to be changed in this regard.
"We saw it in Pike River [coal mine disaster] - everybody walked away scot-free there was well, and that didn't relate to the year-and-a-day rule."
Mr Gallavin said the law should be removed, and a repeal would be straightforward to draft.
"We can't really lay the blame at any particular government or minister in the past but it should've been removed many years ago."
He said it was not possible to know whether the rule had affected prosecutions in the past because, unlike with the CTV, Crown Law opinions were not usually made public.