Exposto contends that she was duped into transporting the drugs by her online boyfriend, who she had flown to Shanghai expecting to meet.
Exposto was acquitted after the judge found she was scammed by her online boyfriend and was unaware she was carrying the drugs.
Professor Monica Whitty's testimony helped secure Maria Elvira Pinto Exposto's initial acquittal, before an appeal court overturned it yesterday and sentenced the Cabramatta woman to death by hanging. Exposto said that she did not know about the drugs, which were discovered by an X-ray machine.
But prosecutors indicated they wanted to appeal the acquittal, meaning that Exposto couldn't return home to Sydney and to her three grandchildren, as there was a still a chance she could face the death sentence, AFP reported in December. She volunteered her bags for customs inspection, according to the Agence France-Presse news service.
"There was clear evidence that she was the victim of an Internet romance scam", Exposto's lawyer, Tania Scivetti, told The Associated Press.
"Criminals will groom these individuals and they will talk to them morning, noon and night, and they develop a very close and trusting relationship", she said.
"I wish you good luck", he said in giving the unanimous ruling.
She had claimed she was the victim of a set-up after she was found with the drugs in her bag after arriving on a flight from China in 2014.
Malaysian lawmakers have voted to amend legislation so that capital punishment is no longer mandatory in drug-trafficking cases.
They were the first Westerners to be executed under the country's renowned anti-drug laws which were introduced in 1983.
In a statement Thursday to News Corp Australia, Foreign Minister Julie Bishop said, "Australia opposes the death penalty in all circumstances for all people".
Malaysia's drug laws are notoriously strict - with a mandatory death sentence for anyone found guilty of carrying more than 50 grams (1¾ ounces). The country carried out four executions in 2017, down from nine the year before.