A multi-million-dollar Tasmanian youth jail had 61 staff to watch over eight inmates in September this year, the ABC can reveal.

The Ashley Youth Detention Centre, in Deloraine, about 45 kilometres from Launceston, houses "juvenile offenders of both sexes aged 10–18 years", the State Government said.

Right to Information documents obtained by the ABC reveal between January and September 2016, staff numbers at Ashley fluctuated between 58 and 64.

During the same period, the number of inmates was as high as 13 and as few as seven.

In September there were eight children at Ashley, managed by 61 staff, a ratio of more than seven-and-a-half staff per detainee.

The future of the 51-bed facility was previously called into question following an incident in July which saw a staff member stood down.

There are three investigations into the incident still underway, including one by police.

The Government said it recognised the Ashley facility did not "support a contemporary model". ( ABC News )

"There's a compelling case to close Ashley, and the evidence grows every single day," Tasmanian Greens Leader Cassy O'Connor said

"We cannot afford this huge wages bill for an ineffective model. It's more proof Ashley is a hugely expensive, over-resourced, and an ineffective model."

Rather than close Ashley, the Labor Opposition wants it used for other purposes.

"It would be hard to argue right at the moment the staff-to-inmate ratio is good value for money," Labor leader Bryan Green said.

"Maybe drug diversion programs and other similar programs can be operated out of there, we do know there is a problem in our society with ice," Mr Green said.

Ashely not perfect: Government

Health and Community Services Union spokesman Robbie Moore argued Ashley needed enough staff to respond to critical incidents.

"Detention is never cheap, and unfortunately you need to make sure you've got adequate staffing levels it needs to cover 24/7," he said.

Procedures at the Ashley Youth Detention Centre came under the spotlight after a number of incidents. ( ABC News )

But Mr Moore said it was up to the Government to lead the way and "take the community on a journey of what the best future operation might be".

In a statement, the Government said it recognised the "current design and environment at Ashley does not support a contemporary model" and it had implemented its Youth at Risk strategy to determine "future options for custodial youth detention in Tasmania".

A drop in detainee numbers two years ago saw staff numbers reduced from 88 to 68 and about $1.5 million knocked off its budget.

The August investigation was one of several probes into clashes at the facility, with Premier Will Hodgman admitting while the methods used on inmates at Don Dale in the Northern Territory were not used at Ashley, the procedures could be improved.

"Those devices, and the practices at Don Dale, do not occur here," he said at the time.

"Does that mean Ashley's perfect? No."

1922 shift away from 'decadent city taint'

Established in the 1860s as the Boy's Training School, the facility was originally located at the site of Hobart's Female Factory, a home for women transported from England to the fledgling colony.

The boys' facility was originally located at the infamous Female Factory. ( Supplied: Tasmanian Archive and Heritage Office )

Before its existence, children as young as eight would be sent to prison alongside adults.

It soon moved north of the city, to New Town, where a history of the institution records that "the boys attended night school after seven hours of manual and agricultural labour each day, gaining the institution a certain renown for its prize-winning pigs".

In 1922, the facility was moved to Deloraine and was renamed Ashley Boys' Home to "improve farm training and remove the 'decadent city taint'".

It was renamed Ashley Youth Detention Centre in 2000.