The class action, which began in the Central Jakarta District Court on Thursday, comes as the Commonwealth admitted in Western Australia this week that evidence used to demonstrate an Indonesian was an adult and not a child in a 2010 people smuggling case was unreliable.

Lawyer Lisa Hiariej told Fairfax Media the class action in Jakarta was being launched on behalf of 31 boys under the age of 18 who were jailed in adult prisons and a further 84 who were held in immigration detention.

She said the Australian government had refused to pay compensation even though the boys had been detained for between three months and two years and nine months.

At the time the federal government had a policy of not prosecuting Indonesian boat crew who were children and sending them home.

Muhammad Rasid told Fairfax Media he was working as a crew member on a boat in 2010 when he was promised 20 million rupiah ($2000) by the captain to "bring goods" from Muara Karang in West Jakarta to a regency in South Sumatra.

He was 16 at the time. "I wasn't suspicious, I needed money," Mr Rasid told Fairfax Media.

Mr Rasid said they were in Central Javan waters when they were approached by three smaller boats carrying nine men of Middle Eastern appearance. "The captain said: 'Hurry, hurry'."

They sailed to Christmas Island where their boat was burnt down and they were held in immigration detention.

Mr Rasid said he was initially held in juvenile detention in Darwin but was then transferred to Silverwater jail in Sydney after an X-ray determined he was born in 1988. He said he did not have a birth certificate with him that would have shown he was born on November 3, 1994.

The method of using wrist X-rays to determine age has now been completely discredited.

"My mum passed away when I was still in Australia," Mr Rasid said. He said his father passed away three months after he returned to Indonesia in October 2011.

Ms Hiariej said the Australian government considered the case settled because the children had been freed from jail and were now back in Indonesia.

"But for the children the case is not yet over because no compensation has been paid," she said. "While in Australia there are many instances where people who were wrongfully jailed received compensation.

In a letter seen by Fairfax Media dated February 25, 2016, Anthony Coles, an assistant secretary in the Attorney-General's Department, responded to Ms Hiariej's request for compensation for Indonesians she alleged to have been minors.

"The Australian government carefully considers the appropriate management and safety of all individuals detained in connection with people smuggling offences, including those who claim to be minors," he wrote.

"In consideration of the information provided above and the response I provided to you on 19 January 2016 I believe the matter is settled."

Mr Coles also wrote that he "respectfully declined" a meeting between Ms Hiariej and Commonwealth officials.

Presiding Judge Ibnu Basuki Widodo said the four defendants in the case were the Australian Department of Immigration and Border Protection, the Australian Federal Police, the Commonwealth Director of Public Prosecutions and the Attorney-General's Department.

"We have summoned them but nobody showed up," Judge Widodo said.

He adjourned the trial until May 30 to give the Australian parties three months to respond.

Meanwhile, at a hearing in the Western Australian Criminal Court of Appeal on February 20, the Commonwealth conceded that evidence which found Indonesian Ali Jasmin was 18 at the time of his trial was "legally unsafe".

Ali Yasmin, also known as Ali Jasmin, spent two years in Western Australia's maximum security prison in Albany after being convicted as an adult on people smuggling charges in 2010.

He was just 14 when he was convicted. The court relied on a wrist X-ray to determine his age even though the Office of the Commonwealth Director of Public Prosecutions had a legalised copy of his birth certificate that stated he was still a child.

A 2012 Australian Human Rights Commission Inquiry called An Age of Uncertainty found there were many young Indonesians whose ages were incorrectly assessed and who consequently experienced significant breaches of their rights.

It said there were 15 cases where young Indonesians were convicted but it was later established by Australian authorities that there was doubt about whether they were adults at the time of their apprehension.

The inquiry found the Australian Federal Police were aware of material that called into question reliance on wrist X-ray analysis but continued to use the procedure as a means of age assessment.