The brother of an inmate found bashed to death at Auckland Prison yesterday wants answers from those who were meant to keep him safe.

Tue Faavae, 23, was discovered yesterday in the east wing of the prison about 11am.

A post mortem today revealed he had been beaten to death by other inmates.

Tonight Faavai's older brother Niko told TV3 News he and his family were still trying to come to terms with his brother's death.

He said they wanted an explanation from the Corrections Department into how anyone would have the opportunity to kill his brother.

"I thought that they were going to be safe in (prison), especially under the watch of the Government," Mr Faavai said.

Detective Senior Sergeant Kim Libby, of North Shore CIB, said Faavae was serving time for aggravated robbery.

North Shore police have launched a homicide inquiry which will begin by focusing on what happened in the east wing before the body was found.

A forensic examination was continuing at the prison and almost 20 police officers were involved.

Department of Corrections chief executive Barry Matthews said the department's thoughts had gone out to his family at this time.

"We are taking this matter very seriously, and we are cooperating fully with the police investigation.

"As with any death in custody there will be a coroner's inquest, and the prison inspectorate and office of the ombudsmen will also investigate the death and the surrounding circumstances.

"As this matter is with the police, we are unable to comment further on specific details as we do not want to prejudice the police investigation," Mr Matthews said.

Corrections was required to give prisoners who were not on specific segregation orders time out of their cells for a minimum of an hour per day. East Division holds 261 prisoners.

"It is simply not possible for each of these prisoners to be given the required time out of their cells one at a time," Mr Matthews said.

"I have asked that the prison inspectorate investigation into the circumstances surrounding the death of Tue Faavae should report back to me on the extent to which the standards, procedures, operational systems and work practices for the proper management of Mr Faavae's sentence were in place and being complied with.

"I have also asked the inspectorate to take into account what changes to procedures and practices have been made in light of recent assaults in the high security area of Auckland Prison, and to determine what further improvements are necessary in order to improve staff and prisoner safety," Mr Matthews said.

Auckland Prison holds 681 male prisoners and contains New Zealand's only specialist maximum-security prison unit.

- NZPA