He was taken to the vets for an autopsy but couldn't be returned to the school because of the chemicals used during the process.
Principal Maria Gillard told the |Herald the school had to break the news to the children during assembly.
"When we told them the bad news in assembly they were very, very upset. We had to explain to them that some bad people had hurt Tama. There were a lot of tears.
"But after a while, the children were pretty good and could laugh about the funny things he'd do. We did the chicken dance for Tama.
"He was a pretty special rooster. They still talk about Tama and there is a memorial out in the garden for him."
However, the school has been left wanting answers after no-one was held to account over his death.
Principal Gillard said the school asked the police several times about the incident but that the police couldn't find enough evidence to prosecute anyone.
A police spokesperson said the school were kept informed throughout the inquiry and the Ministry for Primary Industries was responsible for Tama's body.
Tama's loss has been felt throughout the school with the rooster becoming best friends with many teachers and students.
"The children loved Tama. He started with one of our special needs boys.
"Tama would eat out of his hand and let him pat him. He became very friendly.
"He use to wander through the classroom sometimes and would make his way into the staffroom.
"He was an amazing rooster."
Tama was farewelled by the school at a memorial service in December 2017.