Five birds protected under the Wildlife Act have been found shot dead near Little Barrier Island.
Now the Department of Conservation (DoC) is on the hunt for those responsible, who could face time in jail or a fine of up to $100,000.
Authorities were made aware of the dead birds after a member of the public saw them floating on the water over Auckland Anniversary weekend.
The man, from Auckland, photographed them and reported that it looked as if the birds had bullet holes in them.
DoC has since confirmed that five fluttering shearwaters had been found dead.
DoC's Auckland inner islands biodiversity senior ranger, Yuin Khai Foong, said the seabirds had a conservation status of relict, which meant there was a small but stable population and were therefore absolutely protected under the Wildlife Act.
The discovery was disappointing and he appealed to anyone who may have information about those responsible to come forward.
"People harassing and or shooting these, or any other protected species, are liable for prosecution and face a jail term of up to two years or a fine of up to $100,000.
"We are therefore appealing to the public for any further information about this event,'' Foong said.
"It is very disappointing that some people don't value our native species enough or respect the legal protection they are afforded to treat them accordingly."
Foong said with the long weekend and fine weather, there were many people out on boats in the area who may have seen or heard something that could help authorities.
"Information gathered by the public can help in investigations, especially details which help identify those responsible.
"Taking clear photos of the incident at the time and quickly writing down notes of what was observed can prove to be critical in investigations.''
• Can you help? Anyone who witnessed the incident or has useful information can contact the Department of Conservation on: 0800 362 462 (0800 DOC HOT).