First published in the Sydney Morning Herald

THE number of young people ending up in juvenile detention is continuing to rise and on an average day in Australia more than 600 young people are in detention.

Figures to be released today also show that although the Rudd Government has spoken often about ''narrowing the gap'', the over-representation of indigenous youth in juvenile justice has not improved - they are almost 30 times more likely to be detained than their non-indigenous peers.

The number of people aged 10 to 17 in detention on an average day - not including in NSW - rose 17 per cent from 540 in 2004-05 to 630 in 2007-08. Half of those were in remand and half had been sentenced.

The number of young people in detention during 2007-08 rose from 1.7 per 1000 to 2 per 1000. Almost half were aged 16 or 17.

The Victorian Aboriginal Child Care Agency chief executive, Muriel Bamblett, who is also on the state's youth parole board, said Aboriginal children were disappearing from the child protection system and ending up in juvenile justice.

''A lot of our kids are couch surfing,'' she said. ''They tend to be a group of kids [who] go from family to family or house to house wherever people will take them in … It's not until they actually get into trouble that they start to get intensive case management support.''

Ms Bamblett said this was particularly a problem for children in the child protection system who were not managed by Aboriginal services. They fell through the cracks during adolescence.

The report's author, Rachel Aalders, said that the rise in detention occurred for both indigenous and non-indigenous young people. But Aboriginal young people were still vastly over-represented.

''It's a very large discrepancy,'' she said. ''This report shows that that over-representation certainly isn't improving.''

She said not all of the children who were detained on remand were sentenced.