A prison inmate who died in custody could have been helped before he died if prison staff had properly checked on him, an investigation into the death has found.
Jai Davis died at the Otago Corrections Facility on February 14, 2011, after being placed in a dry cell because of suspicions he was carrying drugs internally.
A coronial inquest into Davis' death is underway in Dunedin.
The inquest was earlier told his death was consistent with the cerebral depressant effects of dihydrocodeine and diazepam (valium). The level of the diazepam was a consistent with therapeutic use.
The Corrections Department has released a report on the investigation it launched into the death, which made numerous recommendations, including ensuring X-rays are undertaken on anyone suspected of carrying drugs internally and an investigation into false records by prison staff.
Prison authorities were aware that Davis was planning to bring drugs into the facility internally after monitoring a phone conversation between him and an inmate.
The conversation revealed Davis expected to be remanded in custody at the prison following a court appearance.
On his arrival on February 11, he was immediately placed in a dry cell and monitored every 15 minutes, which continued for two days, the report by Inspector David Morrison said.
On February 13, staff were instructed to get a verbal response from Davis every hour.
"However no verbal responses were obtained from Mr Davis on the hour throughout the night as verbally instructed by the nurse," Mr Morrison said.
Just before 5am the following day Davis was found dead and in a state of rigor mortis.
The investigation found instructions regarding Davis' verbal responses were not complied with at various times.
"Had these verbal response checks been correctly carried out by the officers, Mr Davis may have been attended to at an earlier time than the discovery that he was deceased at 0511hrs," Mr Morrison said.
Camera footage also revealed that two observations that were recorded as completed at the At Risk Unit (ARU) on the evening of February 13, were not carried out.
Mr Morrison found staff failed to meet a number of Prison Service Operations Manual requirements including inmate observations not completed correctly or accurately, documents not completed and the medical officer not told of why Davis was in the ARU.
Detective Inspector Steve McGregor, Southern district manager, criminal investigations, said police would consider the evidence presented by the Crown solicitor at the inquest hearing to review any evidence relevant to the investigation done in 2013.
Police would then have a better picture as to whether or not the evidence presented departed from that which was originally assessed during the police investigation.
Any decision as to whether the case would be referred to the Crown solicitor would be considered once that review is completed. The review was likely to take weeks if not months.
* the Department of Corrections consider establishing policy for any prisoner suspected of carrying drugs internally to be x-rayed;
* all key prison and health staff are trained on procedures for when an inmate is placed in the ARU;
* prison management investigate issues of non-compliance of instructions at the ARU and false reporting of observations; and
* where a prisoner has been placed on observations, accurate, timely and concise file notes are to be recorded about the prisoner on all occasions.