AN increase in the number of juveniles and indigenous people sent to jail in NSW is being attributed to tougher sentencing in courts, not an increase in crime.
The NSW Bureau of Crime Statistics and Research has released research showing the adult indigenous imprisonment rate rose 48 per cent between 2001 and 2008.
In contrast, the imprisonment rate for non-indigenous people increased seven per cent over the same period.
The jump was despite the NSW government committing to a national approach to reduce the over-representation of indigenous people in prison.
The bureau also released other figures showing an increase in the number of young people being convicted and made subject to control orders.
Annual criminal court statistics show the number of juveniles appearing in court and convicted for at least one offence leapt 17 per cent - from 6318 to 7373 - between 2007 and 2008.
The number receiving control orders, which are served in detention, also increased 18 per cent - from 670 to 788.
Bureau director Don Weatherburn said both sets of statistics appeared to show courts were getting tougher on offenders, particularly in Aboriginal communities.
"One of the ironies of growing public concerns about violence in Aboriginal communities ... is that courts have become much tougher on violent offenders," he said.
This was making it difficult for NSW to meet its commitment to reduce the over-representation of indigenous people in prison, Dr Weatherburn said.
The pledge was made by all states and territories after the Royal Commission into Aboriginal Deaths in Custody in 1991.
"It's been a complete failure," Dr Weatherburn said.
"You can see just how hard this job is when you want to crack down on abuse and violence in Aboriginal communities: the effect is actually to increase the Aboriginal imprisonment rate."
Three-quarters of the increase in indigenous imprisonment in NSW can be attributed to offenders being sent to jail while the remaining quarter was those held in remand.
Dr Weatherburn said all states and territories had become more reliant on imprisonment and had made it tougher to gain bail.
Young offenders faced the same situation, he said, with the increase in those convicted and put on control orders evidently more attributable to a legal crackdown than a surge in juvenile offenders.
"It's odd in the sense that we don't have a rise in crime.
"I'm guessing what's happening here is that it's basically reflective of a much tougher response of police in the first instance and courts in the second.
"Contrary to the popular view that the system is getting softer on juvenile offenders, to all intents and purposes it appears we're getting much tougher."