Staff shortages at Tasmania's troubled youth detention centre have resulted in residents being locked down during the past month, an inquiry has been told.
Health and Community Services Union assistant state secretary Lucas Digney also said at times there was "no assurance" Ashley Youth Detention Centre workers had the necessary skills.
"In the last month we've seen lockdowns because of staffing (issues)," he said on Thursday at a state parliamentary inquiry examining adult and youth detention in Tasmania.
"I know the government don't like to call it lockdown but that's what it is if young people are restricted to their rooms ... they're locked down."
The state government in 2021 pledged to close the centre by the end of 2024 and set up a new therapeutic model and fresh facilities.
A separate commission of inquiry, set to finalise its report in August, last year heard harrowing stories of physical, sexual and verbal abuse of detainees at the centre.
It prompted calls from political parties and human rights advocates for Ashley, which has operated for some two decades, to be shut immediately.
Minister for Education, Children and Youth Roger Jaensch on Thursday said he hoped to provide an updated timeline for the centre's closure in the next few months.
He said the state government had developed a "more sophisticated" model to replace the centre and it would take more time to implement.
Five purpose-built facilities will replace Ashley including a detention centre in the state's south at a location to be determined.
Mr Digney said uncertainty around the new model added to staffing instability.
"For two years we've been asking what the plan is, and we still don't have a plan," he said.
Mr Digney said there had been some improvements in staffing levels in the past few months.
"But certainly in the two years previously, there is no assurance that ... the workforce was stable or they had the necessary skills," he said.
"What we've seen during that time is reduced inductions, no essential requirements for any youth workers except psychometric testing.
"If you pass the psychometric testing you can simply work with young people who are detained there."
Mr Jaensch conceded there had been staffing challenges in the past six to 12 months.
He said restrictive practices, in which detainees are confined to their rooms, were only used for the shortest possible time, as a last resort and for residents' safety.
