Five kea dumped near Arthur's Pass had been shot, the Department of Conservation says.
An initial pathology report from Massey University said evidence pointed to the use of an air-rifle and a shotgun to kill the five kea.
The birds were found piled up on a picnic table at Klondyke Corner in Arthur's Pass on Monday morning last week.
DOC field centre supervisor, Chris Stewart, was appalled by the incident and have referred the matter to the police.
"Kea are endangered and their wild population could be as low as 1000 birds," Mr Stewart said.