KEY POINTS:
A hospital that has called in police after drugs were diluted or replaced with water has confronted staff in the past about theft of medicines, including one person who later died.
Police are looking into the disappearance of controlled liquid painkiller drugs taken from Christchurch Hospital over a period of a month.
The Herald has learned the hospital has dealt with cases of staff taking drugs without permission in recent years, including one in which an anaesthetist was accused of using controlled drugs from the hospital supply, and died soon after.
The cause of the death is unclear.
A hospital spokeswoman would not comment when asked about previous cases, or the present police investigation.
Detective Senior Sergeant David Harvey, who is heading the investigation, said many hospital staff were being spoken to.
Asked if past incidents at the hospital would be considered as part of the investigation, Mr Harvey said: "Yes, obviously it would. We are having an open mind regarding such incidents within the hospital".
Dr Edwin Whiteside, of the Doctors' Health Advisory Service, suspected a doctor or nurse was responsible for taking the drugs, most likely a nurse.
"Nurses are really primarily there to dispense these medicines in the hospital setting," Dr Whiteside told the Herald.
Whether the drugs had been taken for personal use or for selling on was unclear, but there had been cases in the past of health professionals getting hooked on painkillers, or opiates.
It did not appear a big issue, "but it might be just the tip of the iceberg".
"With the access and the temptation, it can potentially be a problem. But it has to be seen as a health issue like any other health issue for health professionals."
Practices around access to controlled drugs had been tightened over the years.
Dr Whiteside recalled a former colleague at Wellington Hospital who did locum work at the weekends to get regular access to drugs, and eventually ended up dying of an overdose.
"My feeling is it's not easy (now) unless you are in a special position of, for example, working in the theatre and you pop an ampoule in your pocket."
The drugs taken from Christchurch Hospital could have been put into a syringe and water inserted instead into a patient's intravenous drip.
