Pago Pago, AMERICAN SAMOA — A retired law professor who has sat on military court panels believes the charges laid in relation to the sinking of the HMNZS Manawanui are unprecedented.

The Navy ship sank in October 2024 off the coast of Samoa after hitting a reef, spilling hundreds of thousands of liters of diesel and oil into the ocean.

Now, three naval officers face a court martial — a specialized military court that tries members of the Army, Navy and Air Force.

The charges include negligently causing a ship to be lost, which is punishable by up to two years in prison.

Former Auckland University professor Bill Hodge, who was in the military and served on court martials, believed such charges had never been laid.

"We haven't lost a ship like this in peacetime, ever, so it must be unprecedented in that regard," he said.

"I think you can safely say it's not only unusual … this is a unique case."

A court martial trial is heard by a judge and a panel of senior military members.

The panel would need to carefully consider the case given there's no precedent, Mr Hodge said.

"Judges like to look at precedent, judges like to look at what all the other judges are doing in similar cases around New Zealand.

"This court martial doesn't have that luxury, but on the other hand, these are responsible senior officers with a tremendous amount of experience and common sense."

Mr Hodge said the charges were laid under the Armed Forces Discipline Act — rather than the Crimes Act — which contains offences that don't apply to civilians.

"The civilian world doesn't include, for example, malingering, it doesn't include AWOL … desertion … disobeying a lawful order … bringing the service into disrepute," he said.

"There's a whole range of things that are absolutely necessary to discipline in a uniformed service."

However, if the officers were found guilty, they could serve time in a civilian prison, he said.

Lesser punishments could include being dismissed from the Navy, or forfeiting rank or seniority.

The NZ Defense Force said the date and location of the trial were yet to be set.

Aotearoa New Zealand's Defense Minister Judith Collins said she was aware of the charges, but would not comment further, given the matter was before the courts.