A group of teenagers has been filmed laughing "Don't be mean to Tweety" while violently throwing a small bird into walls and stomping on it.
The disturbing video was sent to the Herald and featured two former students of John Paul College, who were both current members of the school's First XV.
The SPCA is aware of the incident and investigating.
"I have watched this footage and it is shocking and disturbing," SPCA chief executive Andrea Midgen said.
The bird hops into a corner, where the filmer stomps on the bird several times before he zooms in on it motionless on the floor.
The badly injured bird is picked up by another teen who pretends to eat the bird, before throwing the animal into a wall.
The filmer isn't finished. He picks up the bird from the ground and throws it onto another wall on the other side of the room.
The attack appears to have occurred at a party. Music can be heard throughout the video and boxes of beer are seen on the floor.
The abusers can be heard laughing throughout the 21-second video.
The principal of the Rotorua college, Patrick Walsh, watched the footage and confirmed that two attackers were former students.
"The college is appalled and deeply saddened by their behaviour," Walsh said.
"It is totally unacceptable to treat a defenceless animal in this manner. It is contrary to our core values and we condemn it in the strongest possible terms."
He said that despite the attackers no longer attending the school, the school's Board of Trustees would initiate an urgent disciplinary process to determine their place in the team.
Police said they were unaware of the incident, but the SPCA confirmed it would look into the matter further.