A psychiatrist who treated the man behind a fatal stabbing rampage at a crowded Sydney shopping centre will be referred to health investigators after a coronial inquiry.

Joel Cauchi, first diagnosed with schizophrenia in his teens, was unmedicated and homeless when he stabbed 16 people inside Westfield Bondi Junction in 2024, killing six.

The New South Wales coroner said Dr Andrea Boros-Lavack had provided 40-year-old Cauchi "exemplary" care over a long period, but failed to heed warnings from family that he may be relapsing, years before the attack.

This mistake was one of many that led to the tragedy, the coroner said, also pointing to a series of actions by police and shopping centre security.

Six people - Dawn Singleton, 25; Yixuan Cheng, 27; Jade Young, 47; Ashlee Good, 38; Faraz Tahir, 30; and Pikria Darchia, 55 - died during the attack in April 2024.