Professor Rod Morgan's resignation as head of the Youth Justice Board (YJB) has heaped more pressure on Home Secretary John Reid, but the academic has often been a thorn in his paymasters' side.
Prof Morgan has many years of experience in criminal justice
With a background in academia and criminology, Mr Morgan has never been afraid to attack criminal justice policy in soundbites that both the public and newspaper editors are likely to understand.
Mr Morgan joined the YJB in April 2004 on a three-year contract and little more than a year later he had his first brush with controversy.
Warning that politicians who branded children as "yobs" were risking demonising a whole generation, he seemed to be coming out against the prevailing trend to condemn more and more in the drive to stamp out anti-social behaviour.
There was a contradiction inherent in describing children as the "country's aspirations" and on the other hand condemning them as "thugs in hooded tops", Prof Morgan said.
Less than a year later, he renewed his attack, saying too many young people were being given anti-social behaviour orders and taken through court.
Warming to the theme, he told the Independent on Sunday that there were "adverse consequences to fixing the mark of Cain to a child's forehead" and placed the blame firmly on "misplaced hysteria over teenage crime".
By October last year, Mr Morgan was warning that the youth justice system was reaching "meltdown" with 3,350 children in secure accommodation and the system groaning at the seams.
Again, the academic had a pithy assessment of what had gone wrong, telling the media: "Locking up more children is the equivalent for penal policy of building more coal fired power stations for global warming.
"The likely consequence in the long term is to create more adult career criminals."
But Mr Morgan could not be accused of being an "ivory tower" academic divorced from the realities of the criminal justice system.
Throughout his years of research, he worked as a lay magistrate and chairman of a youth court.
As well as working on a Parole Board, he also spent time on a police authority and as a head of a district council crime and disorder partnership. His work on conditions in custody has been used by both Amnesty International and the Council of Europe.
He is one of the editors of the Oxford Handbook of Criminology, and is preparing a similar work on probation work.
His dual background of academia and criminal justice work led Mr Morgan to be appointed as Chief Inspector of Probation for England and Wales in 2001, leaving Bristol University where he had been professor of criminal justice.
In July 2003 he said low-level probation work could be contracted out to private companies so probation officers could concentrate their efforts on violent and sexual offenders.
By the time of the Queen's speech last year, the government had come around to a similar position.