There is no reason the findings of a Court of Inquiry into the Manawanui sinking could not to be made public, Foreign Minister Winson Peters says.

The New Zealand Defence Force ship caught fire and sunk over the weekend, after hitting a reef in Samoa.

The HMNZS Manawanui was in a "maintenance period" before being deployed to the Pacific, but had undergone trials and been determined safe to be operating.

Peters told RNZ that in "every respect this is a disaster, as far as I'm concerned".

The Court of Inquiry is an investigative body rather than a court of law, and the Defence Force announced on Monday that one was being set up to investigate the sinking.

It aims for "expeditious" fact-finding, and while it can lay blame, it can not hand down punishments and other courts can not use its findings as evidence.

Some parts of the inquiry would likely be public but Chief of Navy Rear Admiral Garin Golding told RNZ other parts - such as those involving commercially sensitive information - would remain confidential.

RNZ understands aspects of the findings related to security would also not be made public.

Peters told RNZ he had "even made submissions" about his expectation that the findings of the inquiry be made public.

"I fully expect it to be what would happen and that was confirmed that is exactly what will happen - a proper full-scale inquiry in which we can have trust in the outcome.

"I can't think of why we wouldn't want to make it public, the public after all are paying for this," he told RNZ.

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Every two years the Commonwealth heads of government meet and later this month they will descend on Samoa. The head of the Commonwealth King Charles is also expected to attend.

Peters did not believe the Manawanui disaster will dominate conversations there "because we're doing our max alongside the Samoan government to fix this issue now".

"There's an outfall of this disaster and we've put all the utilities in to do our best to clean things up, we do not believe that will draw away from the civil service outreach to try and run a conference successfully," he said.

"We've put a lot of work into it, many of our agencies have worked over there to make sure CHOGM in the Pacific, in Samoa, is a success and we're confident it will be a successful outcome."

Peters said the local environment that had been impacted by the shipwreck will be repaired to its "former pristine condition".

He has called on people not to "overegg" things and while "something terrible went wrong....we'll fix it as fast and as quickly as we can".

"We can all ask the what-if questions, but none of us know the answers at this point in time."

Peters said there was nothing "ageing" about the Manawanui and it was a vessel of modern performance.

"It was, I understand, recently the subject of an updating of its mechanical capacity or what have you, all the surveys have been done, and I'm waiting to find out what went wrong.

"There's no use us taking a guess, because that takes us nowhere in terms of factual understanding and factual understanding is what I'm interested in," Peters said.