Minors who were locked up in adult prisons for people smuggling say they could not understand proceedings and thought they were going home.

Vulnerable Indonesian children say they were either given no interpreter or an interpreter who spoke the wrong language during deeply flawed people smuggling prosecutions, leaving them unable to understand court proceedings before their imprisonment by Australia in maximum security adult jails.

The Australian government last year agreed to pay $27.5m in compensation to more than 200 Indonesians who were wrongfully prosecuted and detained as adult people smugglers while they were children.

The children were found on boats carrying asylum seekers to Australia in 2009 and the early 2010s during the last Labor government.

The majority were from poor fishing villages and many were tricked into joining the voyages by people-smuggling ringleaders.