An Indonesian woman accused of murdering a friend with cyanide-laced coffee went on trial Wednesday, in a case that has caused tensions between Indonesia and Australia over the death penalty.

Jessica Kumala Wongso, who is an Australian permanent resident, denies the premeditated murder of her college friend Wayan Mirna Salihin, who collapsed and died after drinking the coffee at an upmarket Jakarta cafe in January.

The case has attracted huge national attention and hundreds of journalists attended the start of the trial, while dozens of the victim's supporters held a small rally outside court demanding her alleged killer be handed a tough sentence.

‘The defendant has deliberately taken someone else's life,’ said prosecutor Ardito Muwardi.

It has also caused tension between Jakarta and Canberra after Indonesian police sought help from their Australian counterparts. Wongso, 27, lived in Sydney until last year, where she studied at a college with Salihin.

Australian authorities agreed to assist after an Indonesian minister guaranteed that Wongso would not be handed the death penalty if found guilty of murder, a capital crime in Indonesia.

However Indonesian officials have since given out mixed messages, with some suggesting the guarantee will not be honoured.

Canberra is sensitive about the death penalty in Indonesia after Jakarta last year executed two Australian drug smugglers. Australia temporarily withdrew its ambassador in Indonesia in protest.

Australian police also faced criticism for tipping off the Indonesian authorities about the drug smuggling syndicate the two men were involved in.

Prosecutors alleged Wongso decided to kill the victim after Salihin, also 27, advised her to break up with boyfriend as he was using drugs.

She invited Salihin to the cafe, where she slipped cyanide into her Vietnamese iced coffee, the court heard.

Salihin collapsed and began convulsing after drinking the coffee, dying soon afterwards in hospital.

Police say that Wongso placed bags on the table to prevent CCTV cameras in the cafe from filming her slipping the poison into the coffee.

Wongso's lawyer, Elizabeth Batubara, said the case against her client was weak.

‘There is no witness and no evidence, Jessica has been painted as a criminal but she is not a criminal.’