Keeping juvenile offenders in an adult Victorian prison is justified because they are not young children, the state government says.
Lawyers for 12 children are challenging in court the government's decision to transfer a group of juvenile offenders to a unit within Barwon adult prison.
Up to 40 young offenders were transferred to the Grevillea unit in November after riots damaged the Malmsbury and Parkville youth detention facilities.
Grevillea is being operated as a youth remand centre and youth justice custodial centre by the Department of Health and Human Services.
Juveniles are held apart from Barwon prison's adult inmates.
The Human Rights Law Centre and Fitzroy Legal Service have told the Victorian Supreme Court trial the transfer was unlawful, and conditions at Grevillea breached the children's human rights.
Senior DHHS managers have admitted the adult facility was not completely ready when the first youths arrived there on November 21.
Renovations to remove items of risk were still under way when one boy used an item to self-harm after he was transferred there.
The teens also did not have access to the educational or rehabilitation programs usually provided in youth detention, and were effectively held in isolation for security and safety reasons.
The government says things have since improved and if there were problems, they were temporary.
"Rights were not limited," counsel for the government Melinda Richards SC said on Thursday.
"Even if they were, there was a clear case of justification."
Ms Richards said the youths who were transferred to Barwon were almost adults, and many faced serious charges.
"While they are still legally children, while they are not cognitively and psychologically mature, these young people have the size and strength of men," she said.
"We're talking about 16- and 17-year-old boys, we're not talking about young children."
Justice Greg Garde has reserved his judgment until next week.
