Sex Crime Consultant; Born November 2 1951; Died June 20 2008

Ray Wyre, who has died aged 56 after suffering a stroke at home, was Britain's leading crime consultant and one of the world's top experts on sexual crime.

Wyre worked with many of the UK's most dangerous offenders, including gangster Reggie Kray and the Grangemouth-born child-killer Robert Black. He also set up the first residential treatment centre for sex offenders anywhere in the world when he established the Gracewell Clinic in Birmingham in 1988.

He was called into many of the biggest murder cases of recent years, working with Anne Marie West as the police prepared the case against her parents, Fred and Rosemary, and interviewing Black for the Scottish police.

As recently as 2006, detectives from Devon & Cornwall Police visited Wyre to secure copies of his taped interviews with Black, who they suspect murdered Genette Tate, 13, in 1978. Although Black never confessed to the crime, Wyre drew him into betraying that he had detailed knowledge of the crime scene.

The evidence Wyre obtained in 1990 into a case already 12 years old could yet prove crucial to an investigation still running almost two decades further on.

Among Wyre's many legacies is legislative change provoked by work he did with television journalist Roger Cook. It was after one of their programmes that child pornography was finally made illegal in the UK as recently as 1987.

Senior police officers and former colleagues will feel the loss of his expertise. Dick Monk, former Assistant Chief Inspector of Constabulary at the Home Office, worked closely with Wyre over a number of years, and has described his death as a "tragedy for law enforcement".

Steve Lowe, a fellow expert operating under the umbrella of Ray Wyre Independent Consultants who will now take charge of the business, described Wyre as "the sharpest man I have ever met."

In recent years, Wyre had combined his child-protection work with unlikely but enthusiastic participation on the professional poker circuit, even contesting televised events.

Born in Hampshire, Wyre left school at 15 to join the Merchant Navy where he served as a submariner. Later, he studied for the Baptist ministry, but eventually opted instead for the probation service.

Between 1981 and 1987, he worked in two maximum security prisons on the Isle of Wight, HMP Albany and HMP Parkhurst. Kray was among his charges at Parkhurst.

At Albany, Wyre pioneered group treatment for sex offenders by giving three or four prisoners appointments at the same time.

For the first time, they were exposed to someone challenging their behaviour rather than being left to reinforce one another's twisted fantasies.

That radical early work in prison led to the establishment of the Gracewell Clinic in Moseley, Birmingham.

Over the five years that it endured, none of its residents was caught re-offending, compared with high rates of recidivism for sex offenders who went on the traditional route to jail and were simply released back into the community.

But pressure from locals who did not want the clinic on their doorstep forced its closure in 1993.

Much of its work was taken up by the Lucy Faithfull Foundation and the Wolvercote Clinic was opened at a secret location, part-funded by the Home Office, but that was also destined to close after a few years. It was one of Wyre's regrets that residential treatment centres were doomed by what he viewed as misplaced public hostility.

In a country that jails only very few extreme cases for life, he felt it was crucial to work with offenders and to understand them.

He always exhorted those he trained and those who listened to him speak at conferences to "think offender but be child-aware" and to "think the unthinkable, imagine the unimaginable, believe the unbelievable".

Despite the many hours he spent looking into the darkest corners of human depravity, Wyre was optimistic and cheerful and used his image, part way between portly cleric and scruffy teddy bear, to his advantage.

His wife, Charmaine, 54, spent a pleasant last evening with Wyre eating out then watching television together just hours before his death in bed.

Wyre is survived by his parents, Derek and Aida, brother David, wife Charmaine, and three children from his marriage to first wife Shirley - Tim, Matthew, and Rebecca. By Marcello Mega