An Australian resident accused of poisoning her friend in a Jakarta cafe may have been acting out of jealousy, a consultant to the Indonesian police investigation says.

Key points: Australian resident Jessica Wongso accused of murdering 27-year-old friend Mirna Salihin with cyanide

Australian resident Jessica Wongso accused of murdering 27-year-old friend Mirna Salihin with cyanide Consultant to Indonesian police investigation says there is no evidence pair were lovers, despite speculation

Consultant to Indonesian police investigation says there is no evidence pair were lovers, despite speculation Ms Salihin's family says they will not ask for death penalty

Forensic hypnotist Kirdi Putra has interviewed the accused woman Jessica Wongso and other key figures in a murder case that has captivated Indonesia.

Wongso is accused of murdering her 27-year-old friend Mirna Salihin by pouring cyanide in her Vietnamese iced coffee at a popular Jakarta cafe.

Indonesian police display iced coffee drinks with and without cyanide. ( Supplied )

The pair met while studying at Sydney's Billy Blue College of Design.

According to Mr Putra, they then drifted apart and did not see each other for at least five years.

In that time, some of Jessica's friends became closer to Ms Salihin, and late last year Ms Salihin married in Bali.

Wongso was not at the wedding.

"A possible motive is some kind of jealousy and revenge," Mr Putra told 7.30.

"First, her friends get taken away, second one, (Mirna) got a better life than (Jessica's) life — that could be a motive.

"It's not quite strong enough, that's why I ask the police to check Jessica's psychological profile to understand more."

Mr Putra has also examined instant messages sent between the pair and interviewed friends of both women and Ms Salihin's grieving husband.

Do you know more about this story? Email 7.30syd@your.abc.net.au

He said there was no evidence supporting the rampant and uninformed speculation in Indonesia that the women were lovers.

"I don't see any supporting materials on their conversations in WhatsApp (an instant messaging service) or their gestures ... or based on information gathered by her husband and friends," he told 7.30.

He has prepared a report on the case for Jakarta detectives.

Wongso appeared 'strangely calm'

Wongso lived in Sydney for 10 years with her parents and siblings and worked for the NSW Ambulance Service until she resigned in November.

She returned to Jakarta on holidays in December and met Ms Salihin in January at Cafe Olivier, a restaurant in the upmarket Grand Indonesia shopping mall.

Wongso arrived at the cafe almost one hour before Ms Salihin.

Mr Putra has seen the CCTV recording of events in the cafe and said Wongso behaved strangely before and after Ms Salihin fell ill.

The footage shows that Wongso ordered three drinks and then left the cafe for a nearby shop.

She bought three items from the shop and returned to the cafe with three separate bags.

She put the bags on the table — obscuring the drinks from view — and several minutes later put the bags on the floor, before Ms Salihin and another friend arrived.

Mr Putra said this could be the moment cyanide was added to the coffee.

The bags were set to hide the coffee so CCTV cannot see," Ms Salihin's father, Edy Darmawan, told 7.30.

Mirna Salihin's father, Edy Darmawan, says the family will not ask for the death penalty. ( Supplied )

Ms Salihin took one sip from her coffee then reacted with shock and said, "This is awful".

Within seconds she slumped back in her seat, critically ill.

Mr Putra said Wongso continued to behave strangely; walking calmly and slowly to the cafe counter to get a glass of water for her dying friend, and later deleting her smartphone data and throwing away the trousers she had worn in the cafe.

Mr Putra also said that before Ms Salihin's death it was relatively easy to obtain cyanide in Indonesia.

It is used as an easy way of catching fish; a small amount in a pond or running water will stun fish and bring them floating to the surface.

"Villagers use cyanide to give poison to the water," he said.

But he said there was no solid physical evidence against Wongso.

'We don't want Jessica dead'

Indonesian police have told 7.30 they are investigating Wongso's life in Australia.

"We also want to know whether the cyanide was from Indonesia or Australia, so we went down there," Jakarta police spokesman Mohammad Iqbal said.

Australian Federal Police are assisting with this case after Indonesia promised it would not seek the death penalty.

7.30 understands they have also helped clean up the CCTV images.

Mr Darmawan told 7.30 the family could lobby the court for the death penalty but they probably would not.

"I don't want Jessica to be dead," he said.

"She was young and we have pity on her.

"What I want is a true honest confession, what Mirna did to her, why [did Jessica] kill her?"

"It will make us feel better in our family."