Gareth Myatt, who died just days into his sentence

Lord Carlile of Berriew QC will chair the investigation, which was set-up by the Howard League for Penal Reform.

The study was announced on Tuesday, just months after 15-year-old Gareth Myatt died in a secure training centre while being restrained by three staff.

Use of segregation and standards in secure homes and Young Offenders' Institutions will also be studied.

Restraint suspended

Gareth, from Stoke-on-Trent, Staffordshire, lost consciousness while being restrained at Rainsbrook Secure Training Centre (STC), in Northamptonshire, on 19 April.

He had served four days of a 12-month sentence for assault and theft.

After his subsequent death, the use of the "seated double embrace restraint" - which involves securing the youngster in a hold while on a chair or bed - was suspended.

I hope that we will be able to make a sensible contribution to the treatment of children in custody Lord Carlile of Berriew

New figures released by the Howard League show that physical restraint had been used 11,593 times in England's three STCs since 1999.

Between them, they hold on average of 190 children at any one time.

'Complex needs'

Lord Carlile, who is the government's independent reviewer of terrorism legislation, said: "My inquiry will consider the various ways that children are treated in penal custody that in any other circumstance would trigger a child protection investigation and could even result in criminal charges.

"We recognise that many of the children held in custody exhibit challenging behaviour and have complex health and social needs.

"But we are concerned about the forcible stripping of young people, long periods of isolation as punishment and the physical restraint of children.

"I hope that we will be able to make a sensible contribution to the treatment of children in custody."

Howard League director Frances Crook said: "Lord Carlile's involvement will certainly give weight to this inquiry.

"I also hope the home secretary will take the inquiry and its eventual conclusions seriously because he obviously trusts the judgment of Lord Carlile."

Adam Rickwood was detained at Hassockfield secure training centre

The three STCs, which are operated by private companies, hold children aged 12 to 17.

A subsidiary of Group 4, Rebound ECD, runs Rainsbrook, as well as Medway in Kent.

Premier Training Services Ltd runs Hassockfield, in County Durham, where 14-year-old remand prisoner Adam Rickwood was found hanged last month.

He was facing a charge of wounding and was said to be upset at being 100 miles-away from his family in Burnley.

Adam, believed to be the youngest person to die in custody in the UK, had not been detained before.

The inquiry will also examine local authority secure children's homes, which hold a total of 206 boys and 53 girls across England and Wales, and Young Offenders' Institutions.