The health watchdog says staff at a south Auckland community hospital failed to realise that an elderly patient was deteriorating until it was too late.
In a decision released on Tuesday, Health and Disability Commissioner Ron Paterson has criticised Counties Manukau District Health Board over the care given to the man at Franklin Memorial Hospital.
The 83-year-old was admitted to the 18-bed community hospital in 2008 with a provisional diagnosis of a chest infection.
Delayed blood tests showed acute renal failure and sepsis.
The patient was transferred to Middlemore Hospital where he died.
Mr Paterson says community hospitals must have systems to handle unstable patients and he has commended the health board for the actions it has since taken.
Boy's death investigated
Meanwhile, police and the Ministry of Health are investigating the death of a boy who drowned while in the care of an Auckland provider specialising in the disabled.
The boy managed to make his way through a locked gate at the facility run by Spectrum Care on Sunday and was found in a nearby creek a short time later.
The ministry says it will talk to Spectrum Care about what happened, and will also monitor the organisation's own internal investigation.
Spectrum Care chief executive Chris Harris says it was the first time someone had got through the locked gate.
The ministry says it does not have any concerns about Spectrum Care.