Seventy crew from the 1600 tonne, Melbourne-based offshore patrol vessel (OPV) and her sister ship HMNZS Wellington have been sent home while the Ministry of Defence and the ships' builder negotiate multiple contractural issues.
The negotiations with BAE Systems, the new owner of the prime contractor for the ships, Tenix Defence, were expected to delay delivery of the ships for up to six months, a ministry spokesman said.
Crews would not be sent back to Australia until the ships were ready to be commissioned.
Both the ministry and the Royal New Zealand Navy declined to comment further until they had briefed incoming Defence Minister Wayne Mapp.
However, Dr Mapp said he understood the main reason for the delay was the weight issue.
"I understand it [Otago] is 100 tonnes overweight."
While the OPVs were strengthened for ice-breaking purposes, the increase in weight might mean they were unable to sail into Antarctic waters, a key Government requirement.
He would have some serious questions for ministry staff at his first briefing later this week, Dr Mapp said.
The weight issue is the latest in a series of problems that have dogged all seven ships designed and built for Project Protector, the Government's $500 million project to improve the navy's capabilities.
Health and safety issues, including the safety of the ship's seaboats, have already caused both OPVs and the four smaller inshore patrol vessels not to be issued with their Lloyds Certification, a safety requirement.
Sorting out the project was one of his top priorities, Dr Mapp said on Monday.
At this week's briefing, he expected to find out exactly what the problems with the ships were, how long it would take to fix them, how much that would cost and whose responsibility it was.
"There are several defence acquisition projects we need to look at, but Project Protector is the most serious because it is a forward-looking issue.
"We need to get these ships into service and they're not ready."
After their experience with HMNZS Canterbury, the navy was refusing to accept the ships and other vessels constructed as part of the project until outstanding problems were rectified.
Canterbury is the only one of the fleet in active service, but the $177 million multi-role ship has been plagued by mainly unspecified problems, along with the well-documented seaboat issue, which have so far required spending of a further $20 million.
In September this year, an independent review of the safety and functionality of Canterbury led by top British ex-naval engineer John Coles found the ship's poor performance in high seas, due to its commercially based design, would have to be accepted.
On the wider project, the review team found the project lacked outside oversight, particularly on safety and technical issues and the limitations of Lloyd's Register certification on a commercial design incorporating significant military features.
The complexity and challenges of Project Protector were underestimated in all respects, the Coles report said.
The size of the project, the management required and the size and skills of the project team were all underestimated, which was possibly the underlying cause of the problems with the ships.
No legal advice was taken on the decision to accept Canterbury and the drawbacks of accepting it were never substantially questioned.
"The approach taken by those involved in key decisions was, it seems to us, 'to crack on come what may' and to hope that perhaps something might turn up," the report said.
