Divers and marine experts have found no evidence of a major fuel spill on a Samoan reef after a New Zealand navy ship ran aground and sank, Samoa's deputy prime minister says.
All 75 people on board the HMNZS Manawanui evacuated safely as the boat foundered about off the coast of Upolu, Samoa, early on Sunday. The ship was one of only nine in New Zealand's navy and was the first the country lost at sea since World War II.
Samoan Deputy Prime Minister Tuala Tevaga Iosefo Ponifasio had earlier said a fuel spill was "highly probable". But on Tuesday he said there was no evidence of oil spilling onto the reefs, ashore and nearby area, except for "small leakages of oil coming from the vessel". That had been contained using specialised equipment, he said in a statement.
The vessel's passengers - including civilian scientists and foreign military personnel - left the vessel on life boats in "challenging conditions" and darkness, New Zealand's Chief of Navy Rear Admiral Garin Golding told reporters. It took five hours for the first survivors to reach land, he said.
One person was treated in hospital for minor injuries and has been discharged, the military said. Up to 17 others sustained cuts, bruises or suspected concussions. An Air Force plane carrying 72 people from the ship landed at an air base in Auckland on Monday night.
NZ will hold a court of inquiry into the loss of the ship. The cause of the accident is not known, but Defence Minister Judith Collins told 1News on Monday she had been told a loss of power to the vessel had led to its grounding.
The specialist dive and hydrographic vessel had been in service for NZ since 2019, but was 20 years old and had previously belonged to Norway, Collins said. It was surveying a reef off the coast of Upolu, Samoa's most populous island, when it ran aground on the reef and began taking on water.
Photos and videos taken from the shore appeared to show the ship listing before disappearing completely below the waves, with a large plume of smoke rising where it sank.
Manu Percival, a surfing tour guide who works in the area where the ship sank, told The Associated Press that oil was not visible from the ship but debris had littered the water and shoreline, and locals were not gathering shellfish as they normally did. It was too soon to know if the "fragile" reef ecosystem had been damaged, he said.
Ponifasio said marine scientists were testing water samples from nearby beaches for any traces of oil.
The military said the ship, purchased for $NZ100 million ($A90 million) in 2018, was not covered by replacement insurance.
The state of NZ's aging military hardware has prompted warnings from the defence agency, which in a March report described the navy as "extremely fragile," with ships idle due to problems retaining the staff needed to service and maintain them. Of the navy's eight remaining ships, five are currently operational.
Golding said the HMNZS Manawanui underwent a maintenance period before the deployment. The ship's captain was an experienced commander who had worked on the vessel for two years, he said.