Those responsible for a botched investigation into the 2010 Fox Glacier sky-diving plane crash should be held accountable, opposition MPs say.
The Transport Accident Investigation Commission (TAIC) is refusing to apologise to the families of the nine people who died in the accident, despite admitting problems with its investigation.
The commission said its decision to allow key parts of the wreckage to be buried days after the crash had limited its ability to determine the true cause.
Labour transport spokesperson Phil Twyford said the findings revealed "appalling incompetence".
"The minister [responsible] needs to urgently call in both the heads of the commission and the Civil Aviation Authority. This is unbelievable mickey-mouse conduct by an agency that's charged with investigating some of our most serious transport accidents."
The minister responsible for the two agencies, Craig Foss, needed to ask some hard questions so the public could have confidence in the transport system, Mr Twyford said.
Craig Foss told Nine to Noon he had confidence in TAIC and the public could also have confidence in the organisation.
He said the organisation has only undertaken two reviews of its original reports or inquiries in the last 25 years.
"Two out of 900 reviews over 25 years gives me full confidence in them. I don't think you'd see that kind of performance anywhere else in the world."
Mr Foss said he would be talking to officials from TAIC next week about some of the "gaps" identified in the report.
TAIC chief commissioner Helen Cull, QC, said an apology to the families of the victims was not necessary, and criticism of the commission had been driven by grief.
Jake Millar's father, Rod, was a director of Skydive New Zealand and died in the crash.
Jake Millar told Morning Report the commission was not admitting wrongdoing.
"We were totally expecting an apology. When we heard her come out yesterday and say very little has changed and they won't be apologising at all, it just stinks of arrogance.
"This whole process has stunk of arrogance."
Mr Twyford said the lack of an apology was not good enough.
"An apology is the least of what's needed. The head of the commission should be put on the carpet of the minister's office, and there needs to be a root and branch review of the agency itself. There's enough in this report by independent reviewers to absolutely get the alarm bells ringing."
New Zealand First spokesperson Denis O'Rourke also said those responsible needed to be held accountable.
"The investigation was a complete botch-up. There's no doubt at all that the wreckage should not have been buried as soon as three days after the accident.
"Investigations overseas - the practice they adopt - is to keep the wreckage for years in case it is needed for further investigation in the future."
Mr O'Rourke said the incident was embarrassing for New Zealand and could affect its reputation as an adventure-tourism destination.
Green Party spokesperson Julie-Anne Genter agreed said the independent review made it quite clear that there were serious problems with the original investigation.
"The commission probably owes the family a serious apology and, if they are unwilling to issue that apology, I definitely think that the minister should be pulling them up."
Mr Foss said in a statement he had full confidence in the commission.
The commission's resourcing was clearly a challenge at the time but the government had increased it so it could boost its investigator numbers to 16, he said.