Some believe the 28 hens and 15 roosters came from one the few preserves in Hawke's Bay - Fish & Game said it was speaking to the owners to see if a large chunk of their nye (flock) was missing.
Rood said in the wild it was illegal to hunt hens but they could be hunted on preserves (with a permit) in Hawke's Bay. There were still strong limits on how many could be caught per day.
The fact that the birds were dumped in an immoral way was, in itself, a crime, he said.
"Dumping like this is a littering offence, pursuant to Section 15 of the Litter Act 1979. Some Fish & Game regions also have some form of regulation which prohibits various types of litter and leaving game on hunting grounds or in public places.
"Exceeding the game bird bag limit is punishable by a fine of up to $5000, plus a further fine of $100 per head of game taken. Community work can also be imposed but the Wildlife Act provides no provision for a custodial sentence for this offence."
Rood said hunters had contacted Fish & Game and were "unhappy and upset that a well-respected game bird could be treated in such a way".
"Pheasants are a difficult bird to hunt at the best of times - they're very cunning and people enjoy pitting their wits against them but often come back empty handed."
Rood said he had never experienced such a situation before in his role at Fish & Game and it was unusual.
"A whole lot of questions need to be answered: where did they come from and why such a large quantity? Why they would be dumped like this leaves everyone asking the question, what's going on?"
Hawke's Bay Fish & Game officers have been given until the end of the week to finish the investigation.
