A tagging programme for child offenders is not working and results in excessive punishment, a charity has warned.
The Howard League for Penal Reform found about 900 children in England and Wales were put under intensive supervision upon release last year.
It says this additional punishment is difficult to comply with, resulting in some children being sent back to jail.
The Ministry of Justice said the programme helped offenders rehabilitate through education.
The Howard League submitted freedom of information requests to every local authority in England and Wales.
It found that between 903 and 918 children were awarded "intensive supervision and surveillance" (ISS) after being released from prison at the midpoint of a Detention and Training Order, the most common jail sentence given to children.
The detention orders allow some children to be released early but require all children to be released at the midpoint under supervision.
The increased supervision programme involves 25 hours of specified activities a week, electronic monitoring and a night time curfew.
As many of the children are not in full-time education, the 25-hour weekly programme involves modules such as education and training, interpersonal skills and changing offending behaviour.
The offenders given increased supervision were originally jailed for crimes such as street robberies.
The Howard League's report, "They couldn't do it to a grown-up: Tagging children without due process," says ISS conditions can be so lengthy and onerous that children find it almost impossible to comply.
Frances Crook, chief executive of the Howard League, said: "We are punishing children repeatedly over several years for a single offence and this cannot be fair.
"Some youth offending teams are applying curfews and tags on children in a mistaken belief that this somehow helps them, whereas the truth is that it is a fast track back to jail.
"We think it could account for hundreds of children ending up in prison each year, not for what they have done or for public safety, but because they go stir crazy on their second or third curfew and tag for an offence committed months or even years ago.
"The only people profiting from this practice are the private security companies supplying the tags."
The report also found the use of ISS varied across England and Wales - 26 local authorities issued an ISS to 10 or more young people, while a further 26 issued none.
The charity is calling on the government to end the use of midpoint ISS.
It says the Ministry of Justice spent £1.4m on private security companies tagging children on Detention and Training Orders in 2010-11.
A Ministry of Justice spokesperson said: "There has been a welcome fall in the number of young offenders going to custody, but re-offending by this group has been too high for too long.
"We want to make sure a full range of options is available for dealing with young offenders. Intensive Supervision and Surveillance is just one of them - it allows young people to serve their sentences while helping them to rehabilitate through education and training."