The Amazonian rainforest where tribe members are accused of killing the student
The suspects apparently boasted to relatives about eating the liver and heart of 21-year-old Ocelio Alves de Carvalho.
A police official in the remote village of Envira said a tribesman, who claimed to have witnessed the murder told him: "The victim was decapitated and cut in half.
"After this, his internal organs, his heart, and parts of his thigh were cut away and eaten."
The victim's remains were retrieved by relatives after police were unable to gain permission to enter the reservation.
Under Brazilian law the military and civil police are not allowed to enter tribal lands.
Detectives were only granted access to question the Kulina tribe's leaders five days after the killing.
The village police chief, Jose Carlos Correia da Silva, said: "At times there is violence between the Indians and people in town but we've never seen a case this cruel.
"The case is so strange ... at first nobody could believe it."
According to Brazil's National Indian Foundation (FUNAI), the Kulina are classified as an "isolated" tribe but some have contact with the non-Indian population.
There are nearly one million Native Indians in Brazil and their land makes up 12% of the country's vast territory.
The country's National Trust said cannibalism is unheard of among Amazonian Indian tribes.