John Plimmer and Bob Long - who grew up in Birmingham, West Midlands - spent two years researching and writing The Inside Track.

It is a fictional account of two children who grew up together, one becoming a detective, the other the head of a crime syndicate.

Neighbourhood gang

Mr Plimmer has used more than 30 years of police experience to create one character while Long, who spent two lengthy stretches in top security jails, weaves in his accounts of life as a hardcore crook.

The two boys - both born in 1947 - got to know each other while roaming the streets in separate neighbourhood gangs in the Lozells area of Birmingham.

At 14, Long joined a boxing club before signing up with the Coldstream Guards, but just two years later he deserted and turned to a life of crime.

In 1971 he was jailed for 10 years for armed robbery and four years after his release he was convicted on another robbery charge and got nine years.

It was only after being released from his second stretch that the pair became friends again.

'Friendly but distant'

In 1966 - the year Long deserted, married and began his criminal career - Mr Plimmer became a PC at Birmingham's Washwood Heath station.

By 1986 he was chief inspector and was made a detective superintendent in 1991 before retiring last year.

Mr Plimmer said: "After his second stretch in the mid-1980s, we bumped into each other a few times and we were friendly but distant.

"We talked about the old days and our families, but it was only when I retired from the CID that we really talked properly.

"I told him about a book that I was writing and he said why didn't I write one about us?"

The pair have spent many hours working on the book at the retired police chief's home in Meriden, Warwickshire. It will be published in the New Year.