The men are two of 16 people given a life sentence for a variety of alleged roles in defrauding the office of South Sudan’s President Salva Kiir of $14 million US dollars.
The two men, 36-year-old Kur Ayuen Kou and 30-year-old banker Anyang Majok Ayuen, returned to South Sudan during the 2011 referendum.
Kur Ayuen Kou was detained at Juba airport in September while preparing to return to Australia for his son's birth. News of his subsequent life sentence rocked his Australia-based family.
“It was just like a death because we haven't heard of life in prison for such cases before, so we nearly mourned it like he's kind of dead person,” his Melbourne-based wife Athieng said.
Athieng said the pressure of the situation prematurely brought on the birth of her now four-month-old son, Dut.

Athieng at home in Melbourne. Source: Supplied
“I did not even have a labour. It was just quick and it happened because I was so stressed and everything was just too much to handle,” she said.
Lawyers for Athieng's husband said he was wrongly implicated through an unrelated association with the alleged ring-leader of the alleged crime.
Melbourne man Nhial Ayuen said his brother Anyang was also falsely accused and sentenced to life.
He said there is no charge sheet, conflicting evidence and more questions than answers regarding the case.
“In court they asked if they receive the money and they say yes. And then the government lawyer asked what is the case against Anyang and they say yes so it's very strange situation. We don't think there's evidence against half these people, not just my brother,” Mr Ayuen said.
Related reading
Australian man dies amid deadly conflict in South Sudan
SBS also spoke to a lawyer who once worked in South Sudan's Justice Ministry. He declined to reveal his identity, fearing repercussions for criticising the system, but said the rule of law had effectively collapsed in his former homeland.
“You can be arrested and you can be put in the jail without any questions or investigations and you can stay there without fair trial you can stay there for long time,” the man said.
The two Australians are among six of the prisoners to be granted an appeal before a panel of three judges. South Sudanese lawyers have advised their families not to request consular support from the Australian government until that process is exhausted but recent political and military instability in the country means there's no certainty if or when this will take place.