The family of a prisoner whose death helped spark the Mt Eden Prison fight club inquiry says a new report raises disturbing questions about Department of Corrections and police investigations.
Nick Evans' family has lodged a complaint with the Independent Police Conduct Authority (IPCA).
Inspector Colin Ropiha's report, which RNZ has obtained, looks into the circumstances of Evans' death in hospital in June 2015.
The report rejects claims Evans, a P dealer, was dropped from a balcony at the remand prison in Mt Eden in the months before his death.
"There is no evidence to suggest that Mr Evans was subject to being 'dropped' over a balcony or having been associated with the 'fight club' activities whilst he was in custody."
The report notes Evans' prison medical history recorded that he was assaulted by an inmate on 31 March, shortly after being admitted to Mt Eden.
He complained of chest pain and asked for medical help five times, but it took 17 days until he was seen.
He never saw a doctor or nurse about his injuries, and it was a physiotherapist who helped him fill in an ACC claim form and who discharged him in mid May. He told her of the assault.
"He demonstrated the dumping action to the physiotherapist which she described as being like a rugby spear tackle," wrote Mr Ropiha.
The report states the physiotherapist reported that she conducted a thorough assessment and "during this procedure Mr Evans stated it was painful when he coughed".
Two weeks later Evans was transferred to Ngawha Prison in Northland, and within 24 hours was sent to hospital. He died two weeks later.
His family have written to the coroner outlining their concerns and have lodged a complaint with the IPCA saying police did not appear to have conducted a thorough investigation.
"Although Mr Ropiha provided evidence in his report that the assault occurred, he did not mention this in his executive summary or in his key findings," their complaint says.
"His report treated the assault as it was irrelevant. One gets the impression police also treated it as irrelevant."
A pathologist found Evans died of septic shock from a lung infection, and said there was no evidence of violence or injury contributing to his death.
His family argue that could be because the autopsy occurred 11 weeks after the assault.
The Ropiha report clears Ngawha Prison, where Evans spent only a few hours, but faults Serco's care of him.
He was not told how to apply for medical help until seven weeks after he arrived in Mt Eden, and was never given the full health check all inmates are meant to get in their first five days.
Corrections has refused to tell RNZ if Serco has been penalised in any way for this.
An investigation by the Chief Inspector into allegations about fight clubs in Mt Eden Prison blamed endemic violence at the jail on under-staffing by Serco. Corrections knew at the time about this understaffing and that the prison was unsafe.
The report found that Serco used inadequately qualified staff to do medical assessments, and found cases of it overlooking requests for medical help and of poor triaging so that prisoners didn't get seen in time.
The coroner said he had spoken with police last week and "they are reasonably satisfied with their investigation" into Evans' death.
Corrections said it would not be commenting until after the coroner's inquest, which is expected to be held in the first half of next year.