An estimated 1,500 children in England are locked up by the state for their own or others’ safety at a cost of a £300m a year, new report reveals.

A new study by Anne Longfield, the children’s commissioner for England, shows that there were 1,465 children in England securely detained in 2018.

An estimated 873 of these children were held in youth justice settings, 505 were in mental health wards and 87 were in secure children’s homes for their own welfare.

This costs the public purse around £300m a year, Ms Longfield calculated – although this excludes what is spent on ‘invisible’ children whose settings the state does not have information about.

Medium Secure Mental Health Settings are the most expensive form of provision, at £1,611 a day or £588,015 a year.

Secure Children’s Homes have an estimated cost per child of £210,000 per year, with Secure Training Centres at £160,000 a year and Young Offender Institutions at £76,000.

The commissioner’s research also found 211 children whose Deprivation of Liberty has been authorised by a court but whose whereabouts in the system is invisible because they do not fit into any of the categories for which there is published data.

‘Locking children up is an extreme form of intervention,’ said Ms Longfield.

‘We are spending millions of pounds on these packages of care and yet there is far too little oversight of why they are there, their journeys into this system and the safeguards in place to protect them once they are there.’

Responding to the report, Cllr Anntoinette Bramble, chair of the Local Government Association’s Children and Young People Board, said: ‘Any decision to deprive a child of their liberty is taken extremely seriously, and only made in cases where there is no other option available to protect that child or those around them.

‘These children will have extremely complex, significant needs, and councils work hard with their partners including in health and youth justice, to make sure these placements provide the support children need to overcome those issues in order to try and help them go on to live safe, independent lives.’

Renuka Jeyarajah-Dent, deputy CEO of the children’s charity Coram, said the report revealed an ‘alarming safeguarding failure’.

‘It is unacceptable that over 200 children have been essentially “lost in the system” and placed in settings about which we have no information,’ she said.

‘We have no idea how long these children have spent in these institutions and no idea as to whether they are receiving interventions that best respond to their needs.’

Ms Longfield urged local authorities to provide her office, Ofsted and the CQC with data on the number of children deprived of liberty in their area at any one time, the legal basis for that deprivation of liberty, and where those children are living.

Ms Jeyarajah-Dent welcomed this call from the commissioner and said that councils would need to take ‘urgent steps to gain a clearer picture of each child’s history within the system.’