Iced Coffee Killer - Jessica Wongso

In Sunday's 7News Spotlight Liam Bartlett meets Australia's ‘Iced Coffee Killer' - Jessica Wongso, released on parole in Indonesia last year after serving for 8 years in detention.

Almost a decade ago, Australian resident and former NSW Ambulance worker Jessica Wongso was convicted of brazenly and fatally poisoning her former best friend's iced coffee with cyanide in a busy Jakarta café.

It was January 6, 2016, and Wongso was catching up with Mirna Salihin at one of the city's classiest cafes for the first time in four years.

She'd taken the liberty of pre-ordering Salihin a drink. But seconds after she took her first sip, she began convulsing and foaming at the mouth. Just over an hour later, Salihin was dead.

Described as the most compelling murder mystery in Indonesian history, the case shocked Australia and sparked international headlines.

Now out of prison and granted a Judicial Review in the Indonesian Supreme Court having served only eight of a 20-year sentence, Wongso has bizarrely become a successful social influencer and is desperate to rewrite history.

In this major 7NEWS Spotlight exclusive, Wongso – who has always maintained her innocence – comes face-to-face with award-winning correspondent Liam Bartlett in her first ever tell-all interview.

Bartlett presses Wongso in the confronting sit-down on every aspect of the case, including accusations she was motivated by jealousy, her suspicious behaviour in the hours before the murder, her bizarre tendency to smile throughout the trial, and her thoughts on likelihood of acquittal.

"They still can't prove anything," Wongso tells 7NEWS Spotlight in the at times uncomfortable interview.

We also hear for the first time from the Australian woman who helped seal Wongso's fate. Former boss Kristie Carter sits down exclusively with Bartlett to reveal for the first and last time the ‘erratic' behaviours she witnessed in the lead up to the killing, and the trauma she and others endured from Wongso.

Liam Bartlett said: "There's something you just can't pin down about convicted murderer Jessica Wongso. Is she innocent as half the Indonesian population seem to think? Or is she – as those who are convinced of her guilt like to put it – completely mad?

"Either I'm sitting in front of a cold, calculated killer who murdered her best friend on the basis of simple jealousy, or a young woman who is a terrible victim of circumstance.

"It's a plot worthy of a soap opera. But now, nearly a decade on, a family still grieves the incomprehensible killing of a beautiful young woman by her one-time best friend, who continues to protest her innocence."