The captain and second officer of a cargo ship which grounded off New Zealand last year pleaded guilty on Wednesday to causing the country's biggest ever sea pollution disaster, officials said.
The officers were in charge of the Liberian-flagged Rena when it ploughed into a reef on October 5, releasing an oil slick that killed thousands of sea birds and fouled beaches in the North Island's pristine Bay of Plenty.
The men, both Filipinos, pleaded guilty to operating a ship in a dangerous manner and criminal charges of attempting to pervert the course of justice by altering records after the accident, Maritime New Zealand (MNZ) said.
At a hearing in the Tauranga District Court, the captain also admitted discharging harmful substances from the vessel, MNZ said.
It said the men, whose names were suppressed when they were released on bail last year amid fears for their safety, could face lengthy jail terms. They will be sentenced on May 25.
The Rena hit the reef 22 kilometres (14 miles) offshore in clear conditions as it steamed towards Tauranga, New Zealand's largest container port, becoming stranded and eventually breaking in half in January, when the stern sank.
The disaster triggered a complex salvage operation, which is still continuing as crews slowly remove containers from the wreck, and a massive clean-up in the popular tourist spot involving 5,000 volunteers.
The Bay of Plenty, which contains marine reserves and wetlands, teems with wildlife including whales, dolphins, penguins, seals and rare sea birds.