Chilling never-before-seen footage shows Australia's most prolific mass murderer confess to his horrific crimes when he mistakenly thought the camera was off.

A creepy smile warps the face of murderer Martin Bryant as he baits police with a vague confession during a recorded interrogation after he mercilessly shot 35 people to death and left 23 others injured in the 1996 Port Arthur massacre.

"I'm sure you'll find the person who caused all of this," a young Bryant tells police shortly before he raises his hand and motions towards himself as he mouths the word "me".

"You shoud've put that on recording," he adds.


While Bryant appeared confident that police missed the confession and would not be able to prove his admission, a police officer tells the murder accused that the video had not been shut off and that his statement was on record.

The disturbing footage was aired during a Sunday Night investigation into Bryant 20 years after he loaded up his yellow Volvo with three guns and went on a horrific shooting spree on April 28, 1996.

The records of Bryant's interrogation also show the blue-eyed killer smiling and laughing as he looks at pictures of his slain victims, continually pressing detectives for more information on how many people he killed.

"How many people died altogether then?' Bryant asked.

"Including the people at Seascape - 35," the police officer responds.

Bryant continues to ask the officer for more information, always appearing on the edge of laughter, as he either revels in or remains oblivious to the pain and suffering he caused to the victims and their families.

"How many people injured? Many?"

"Quite a lot," the detective said.

"How many's quite a lot? Like a dozen?"

Bryant, whose IQ was found to be "lower than more than 98 per cent of the normal population", also appeared animated when police bring out an assortment of arsenal used in the violent rampage.

The then 28-year-old - whose curly, blond hair brushes against his shoulders - smiles as he re-enacts how he held the gun that he pointed at his 35 victims, two of which were two young children.

Bryant appears quite arrogant in the video and boasts of his crimes. Photo / Channel Seven
Bryant appears quite arrogant in the video and boasts of his crimes. Photo / Channel Seven

He goes on to talk about how being locked up is "not fair" before suggesting that he should undergo "training" instead of being incarcerated, seemingly unable to grasp the seriousness of his crimes.

"I mean, I know I've done the wrong thing but surely they can train me say, for a few months, a year, for what I've done - we can work things out."

Psychologist Paul Mullen said Bryant was not placed in the type of special schooling that would have suited someone with his levels of intelligence - in his opinion because Bryant's attractiveness meant he could assume a somewhat normal existence.

He said during the investigation Bryant had wanted to be the "centre of attention" and that he had basked in his international notoriety following the tragic massacre.

Drawings done by Bryant in coloured crayon show a simplified version of events, where a black stick figure moves from table to table, hunting and shooting his victims.

Bryant's lawyer, John Avery, said Bryant wanted to be "the fellow who had committed the worst crime in Australian history", something he was convinced of until he saw him wheeled in, cuffed to a chair.

"Once I saw him, because I could see that without the gun, without the weapon, he was nothing. He was a sad, insipid little boy," Mr Avery told Sunday Night.

Mr Avery shared a handwritten, poster-sized confession penned by his client after he had decided to change his not guilty plea to guilty.

He said Bryant had always been sensitive about his lack of intelligence and when he told the murderer that he would be portrayed as "simple Martin" in court he soon decided to amend his plea.

Scattered with spelling errors, Bryant wrote: "I, Martin Bryant, wish too[sic] plead guilty too[sic] all charges - 72"

Bryant was found guilty on 72 separate charges including murder and attempted murder in the Tasmanian Supreme Court.

He was sentenced to 35 life sentences - or 1035 years without parole.

The blond killer, now 48, has been incarcerated at Risdon Prison, near Hobart, ever since.

Bryant has reportedly stacked on the weight in prison - reaching a massive 160kg - and is also believed to have been involved in an assault on a nurse which resulted in a broken jaw.

- Daily Mail