An investigation is underway into the death of a nursing home patient and the hospitalisation of nine others from salmonella food poisoning.

NSW Health says cases of salmonella first appeared in aged care homes on January 21. An investigation has uncovered 23 cases in 10 facilities across South Eastern Sydney, the Illawarra and ACT.

The Illawarra Retirement Trust says 20 of the cases happened at its care centres. Chief executive Nieves Murray says it is possible pre packaged products supplied by a third party, like salads, are behind the outbreak. Early inquiries show the species of salmonella is associated with manure used in growing salad vegetables, not meat.

Click here to read the full article at ABC News.