Survivors of a 16-hour siege in a Sydney cafe on Sunday told of their terror during the deadly standoff, as a jihadist gunman threatened to kill people "one by one".

Iranian-born, self-styled cleric Man Haron Monis held 17 people hostage at the Lindt chocolate cafe in the heart of the city's financial district before being killed when police stormed the building in the early hours of December 16.

Two hostages -- cafe manager Tori Johnson and barrister and mother-of-three Katrina Dawson -- also died in the siege, which shocked Australians and people around the world.

"I literally thought he was going to shoot us so that everybody can see through the window," survivor Harriette Denny told commercial broadcaster Channel Nine.

"Knowing that you're about to die is kind of hard, the desperation you feel, the fear," said the 30-year-old, who was pregnant at the time of the hostage crisis.

"You lose hope, thinking about your family outside, thinking there's nothing you can do to get yourself out and it's very hard."

Sydney Siege
Iranian-born, self-styled cleric Man Haron Monis held 17 people hostage at the Lindt chocolate cafe in the heart of the city's financial district before being killed by the police. - EPA Photo

The siege horrified Australia and prompted a mass outpouring of grief that saw thousands of flowers laid near the cafe in Martin Place.

Hostage Marcia Mikhael said Monis, who had a history of violence and extremism, told her he had a "plan" to die in the standoff.

[PHOTO GALLERY]: GUNMAN TAKES HOSTAGES IN SYDNEY CAFE

"I knew he didn't want to get out of there alive and because of that, I was very scared about how it was going to end," the 43-year-old told Channel Seven, struggling to hold back tears.

The interviews, for which channels Seven and Nine reportedly paid hundreds of thousands of dollars, came just over a week after an inquest opened into the siege.

The New South Wales coroner was told in graphic detail how Johnson was made to kneel down and shot in the back of the head after a group of hostages escaped.

Dawson was killed after six fragments of a police bullet, or bullets, ricocheted from hard surfaces and struck her body.

[MORE PHOTOS]: SYDNEY SIEGE: UNEASY ENDING


Survivor John O'Brien, 82, said Monis was "ranting and raving" about Prime Minister Tony Abbott and threatened to kill everyone in the cafe.

"He threatened us when he said, because Tony Abbott wouldn't come to the phone, he said Tony Abbott will have all your blood on his hands when I kill you all, one by one," O'Brien told Channel Seven.

A separate report into the siege commissioned by the federal and NSW state governments has been completed and is expected to be published this month.