A police strike force has been set up to investigate a suspected poisoning at an aged care facility which has left one woman dead and two other residents in hospital.


Homicide squad detectives have joined local investigators in Newcastle after staff at John Hunter Hospital raised the alarm when three residents from the Newcastle nursing home were presented with similar symptoms on two consecutive days.


One woman, 83, was taken to hospital on October 18 but later died.


A 91-year-old woman and an 80-year-old man were also taken from the facility to John Hunter Hospital on October 19. They remain in a serious condition in hospital.


Detective Inspector Graeme Parker confirmed that Strike Force Correa had been set up to prepare a report for the coroner and look at the other two incidents.


He also confirmed that the two other patients had produced similar symptoms to the dead woman.


However, Fairfax Media understands that all three became hypoglycaemic after being injected with high levels of insulin.


Tests confirmed the levels of insulin and detectives were called in when experts said it had to have been injected into them.


Police seized documents after conducting a search warrant at the aged care facility last week.


It is understood senior investigators are now deciding whether they need to look back at other deaths or hospitalisations.


A statement from the facility owner said the aged care home was ''fully co-operating'' with the police.


The Newcastle Herald