Last year 1,889 boys aged 15 and 16 were remanded to prisons and remand centres - a rise of 72 per cent since 1992.
The Penal Affairs Consortium, a grouping of 31 organisations, wants the Government to end the practice which was abolished for girls in 1979. The rise reversed a previous steady fall from 4,812 in 1976 to just over 1,000 in 1992.
"Keeping juveniles before trial in overstretched penal establishments, together with young adults more sophisticated in the ways of crime, is a recipe for intimidation, bullying and confirming young people in criminal habits, " says the report. It adds that it is unfair to expect prison staff to look after vulnerable young people in these unsuitable conditions.
Many of the boys appear to be much younger than their ages and give the impression of being severely damaged children likely to pick up further criminal habits, notes the report.
The 1991 Criminal Justice Act includes provision to end such remands which will be implemented when the Government's programme to provide 170 local authority secure places is completed by mid-1997. But the consortium wants courts to consider alternatives such as bail support schemes, short-term fostering and open residential places which should be provided in law by local authorities and probation services using Government money.
Of the 15 and 16-year-olds remanded in custody between October 1993 and September 1994, most were charged with non-violent offences such as burglary or car theft. Black youngsters were disproportionately represented and there were large regional variations.
Per 10,000 of 15 and 16-year-olds, 136 were remanded in Manchester, 129 in Sunderland and 107 in Calderdale. There were no custodial remands in Plymouth, Portsmouth, Walsall and the Wirral, probably because community-based services were available.
Paul Cavadino who chairs the Penal Affairs Consortium, says: "Everyone working in the penal system regards holding of remanded juveniles as indefensible. The ending of this Dickensian practice is long overdue."
Juveniles on remand, is available free from the Penal Affairs Consortium, 169 Clapham Road, London SW9 OPU.