Sydney siege anniversary 'extremely difficult'

It's been one year since Tori Johnson and Katrina Dawson were killed during the siege at Sydney's Lindt Cafe. Photo / Getty Images

The NSW State Coroner has taken the unusual step of issuing a public statement to mark the anniversary of the Lindt Cafe siege, noting that Tuesday will be "extremely difficult" for those touched by the tragedy.

Coroner Michael Barnes, who is undertaking the enormously complex inquest into the siege, offered his deep sympathy to the families of siege victims Tori Johnson and Katrina Dawson.

"In the days following the siege, we saw a monumental outpouring of emotion as thousands of people paid their respects to Katrina and Tori and Martin Place," Mr Barnes said.

"One year on, we need to remember these feelings will not have subsided, particularly for those impacted by the siege.

"In some instances, it could be worse."

Mr Barnes said families who have lost loved ones deal with their loss in their own way and need support.

"You cannot put time limits on grief," he said.

The inquest into the events of December 15 and 16, 2014, is one of the largest and most complex inquests ever undertaken in Australia.

It began in January, unusually soon after the siege because of the urgency of the national security and public safety implications surrounding the tragedy.

Mr Barnes noted the inquest, which has been "a challenging and confronting process for the families of Tori and Katrina", is the first time a coronial inquest has examined a potential act of terrorism.

"These endeavours are justified because the families of Katrina and Tori are entitled to know whether the incident could have been managed in a way that would have avoided their deaths," he said.

"Further, the people of Sydney deserve reassurance that the law enforcement and intelligence agencies will, whenever possible, prevent similar incidents occurring in future and, if it is not possible, the response will be in accordance with world's best practice."

Mr Barnes is due to deliver his findings in mid-2016 and they will be the culmination of a huge investigative effort by lawyers and the police of Strike Force Verum.

- AAP