“In the preliminary findings of his current review of the Youth Justice System for the British government (2016) Charles Taylor commends a network of ‘secure schools’ to replace the existing Young Offender Institutions and Secure Training Centres,” said Prof Pitts.

“The clear implication is that these institutions have failed: to prevent reoffending; to offer decent education; to provide the necessary therapies and to keep the young people safe from addiction and assaults by staff and other inmates.”

The Professor also pointed to previous incarnations which had also failed such as Borstals, the Approved Schools and the Young Offender Institutions.

He said: “The numbers of young people entering custody has fallen markedly in recent years and, as a consequence, those who do tend to be more troubled; to have committed more serious offences and to be serving longer sentences.

“If the new kind of prison proposed by Charles Taylor is to succeed where all of its forerunners have failed, he must first find a remedy to this apparently endemic propensity for failure.”

Prof Pitts spoke out after the Guardian revealed at the weekend (Saturday 27 February), that a letter he sent 13 years ago, was at the heart of the new scandal engulfing the G4S Secure Training Centre at Medway Kent.

In his 2003 letter to a cabinet minister, the Director of Children’s Services at G4S, senior officials at the Home Office, the Social Services Inspectorate and the Youth Justice Board, Professor Pitts wrote about allegations by ‘whistle blowers’ of abuse and bullying taking place at Medway.

The allegations closely mirrored the behaviour revealed by a recent Panorama documentary and the Guardian investigation could also find no evidence that action was taken in response to Professor Pitts letter to remedy this situation.

Shortly before publication of the Guardian investigation, G4S announced it would be selling all of its Children’s Services including its contracts for Medway and another Secure Training Centre at Oakhill, Milton Keynes.