SYDNEY - An inquest by the New South Wales Coroner's Court into all aspects of last month's deadly Sydney siege will begin on Jan 29, it was announced on Wednesday.

It will examine the deaths of hostages Katrina Dawson and Tori Johnson, and the hostage-taker Man Haron Monis. They were killed in the Lindt Cafe in the CBD thoroughfare of Martin Place in the early hours of Dec 16.

One issue the inquest will focus on is whether their deaths could have been avoided.

"The aim of the inquest will be to determine how the deaths occurred, the factors that contributed to them and whether they could have been prevented," a Coroner's Court spokesman told Fairfax Media.

On Sunday Fairfax Media reported Dawson died when she was struck by a police bullet that may have ricocheted and hit her heart. Police have not commented on the report.

It is believed Monis executed Johnson, the cafe manager, by shooting him in the back.

Monis was killed when police stormed the cafe in a hail of gunfire after a 16-hour stand-off.

The crucial minutes between Monis firing his first shot and police storming the cafe will also be examined.

The State Coroner will determine applications to participate in the inquest from lawyers representing the families of those who died, the police officers involved and any other parties who apply to give evidence.