South Australia has the nation’s highest rate of unsentenced prisoners in jail, new Australian Bureau of Statistics data has shown.

Of the state’s 2488 adult prisoners in 2013/14, 35 per cent or 868 people were unsentenced, the data released yesterday shows.

This compares with the Northern Territory that has 28 per cent of prisoners unsentenced and New South Wales where 26 per cent await sentencing.

It adds to mounting concerns from stakeholders about overcrowding of the state’s prisons who say the system is at “breaking point”.

Prison capacity figures from the Department of Correctional Services 2013-14 annual report show that the Adelaide Remand Centre is already over capacity with 287 prisoners for 267 places. Mobilong Prison can accommodate one more prisoner while Port Augusta and Cadell Training Centre have less than 10 places available.

The ABS figures, recorded to June 30 this year, show a 10 per cent increase state and nationwide in the total number of adult prisoners.

This is a 10-year high across the board.

Law Society of South Australia president Morry Bailes said it was unacceptable that more than a third of SA’s prisoners were on remand.

“I did not expect the rise in prisoners to be so sharp. A 10 per cent increase in 12 months is a considerable jump,” Bailes said.

“To accommodate prison overflow, officers have been forced to place some prisoners in police cells. There have even been reports of prisoners being driven around in transit vans because there’s been nowhere to put them.”

He said alternative measures must be explored, such as bail accommodation for low-risk individuals that the Government is currently considering.

Attorney General John Rau said he was examining the justice system from first arrest to release to identify opportunities to reduce prisoners on remand.

“I acknowledge we have larger numbers of prisoners in some areas when compared to other states, this is part of the reason I have been given the portfolio of Justice Reform,” Rau said.

“There are a broad range of sentencing options and these, along with other strategies like moving people through the remand stage more effectively, could help relieve the pressure on our prison system.”

The DCS report says in 2013-14 $24 million was spent on increasing prison capacity with a new 108-bed accommodation unit at Mount Gambier Prison and 58 beds across Yatala Labour Prison, Cadell Training Centre and Mount Gambier.

Shadow Attorney-General Vickie Chapman said the figures reflected a problem with processing times.

“It is critical that matters are progressed through the courts as quickly as possible,” Chapman said.

“It’s not cheap keeping people on remand who may not need to be there.”

The statistics showed that SA prisoners convicted of murder and related crimes could expect to spend more time in prison than anywhere else in the country. The average time spent in jail from arrest to release was 21.6 years. This doesn’t account for differences in legislation.

The most common offence or charge of SA prisoners was acts intended to cause injury (15 per cent or 385 prisoners) followed by offences against justice procedures, government security and operations (13 per cent or 335 prisoners) and sexual assault (13 per cent or 331 prisoners).

Commissioner for Victims’ Rights Michael O’Connell said the sentencing decision was “keystone” to the criminal justice system but the increase in the number of offenders serving time didn’t necessarily mean a tough on crime stance.

“The number of offenders in our State’s prisons does not surprise me,” O’Connell said.

“Parliaments echoing the public disquiet (about the prevalence of crime) have revised many sanctions: more offences are punishable by imprisonment and some maximum terms of imprisonment have been raised.

“Whether the increased prison population is the prime reason for the overall drop in crime, is arguable.”

In October the State Government announced a $2 million 24-bed expansion of Mount Gambier prison.