The coronial inquest into chemotherapy under-dosing in South Australia has been expanded following the death of another patient.

Of the ten acute myeloid leukaemia patients who were under dosed at the Royal Adelaide Hospital and the Flinders Medical Centre, four have now died, three have relapsed and the fate of three more is unknown.

During treatment the affected patients received only a single daily dose cytarabine when they should have received two.

A formal independent review which handed down its findings last year concluded that the under-dosing reflected a series of significant failures in clinical governance at the Royal Adelaide Hospital haematology unit and a lack of adequate knowledge, skill, care and judgment by some clinicians.

The coronial inquest continues.