Every Sunday afternoon, Paul Ravilious steels himself for his obligatory weekly phone call.

But the call is not from his mother-in-law, his aunt or his children. It is from the most notorious prisoner in the country, armed robber Charles Bronson.

Paul has been friends with the inmate - dubbed Britain's most dangerous prisoner - for more than four years. They have been pen pals since Paul became interested in the prison system and decided to find out more.

Since then the pair have collaborated on a biography, a book of poems and a TV documentary.

Over the years, Bronson and Paul have forged an unshakeable alliance. Bronson has grown to trust the father of four to look after almost all his affairs on the outside and Paul has come to rely on the prisoner for advice and support.

Because of Bronson's Category A status as a dangerous inmate, the two have never met. But they talk every week on the phone and Bronson sends Paul at least three or four packages of mail and papers every week.

The two even plan to live together when Bronson is released. Paul, of Bayford Road, Littlehampton, said: "If he was released, Charlie has already told me he's going to get a cottage and shack up with me. I can't wait. I would definitely be happy to live with him."

Paul believes the convict, who changed his name by deed poll after seeing the Death Wish movies, is a misunderstood victim of his own tough-guy image.

He said: "There is more to Bronson than meets the eye. He is a very clever guy, he's not as vacuous as people think he is. He's very chameleon-like. In front of a bunch of vicars he would be going, 'I've found Jesus'. In front of some homies he would be like, 'Hey brothers'. He's that sort of bloke.

"I do know the real Charles, and the real Charles, apart from when he goes off on bad tangents and when he takes hostages and stuff like that, is a really genuine person.

"Deep down he knows he has ruined his life. His infamy is a trap now. He's got to go one step further every time to stay in the news. He's created this image and now he has to live up to it. I think it massages his ego to hear that so many other criminals look up to him and admire him.

"He wants to keep it that way. I think that is why he does something new every year - why he takes hostages whenever he can and stages the rooftop protests.

"In isolation he is king of his own kingdom, even though it is a 10ft by 8ft cell."

In his biography of Bronson, Concrete Coffin, Paul writes about the con's torment at spending 24 years in solitary confinement.

Bronson, 49, was jailed for armed robbery at the age of 21. He has spent his entire adult life behind bars, almost always in solitary confinement.

According to Paul, this long isolation has hampered Bronson's ability to form relationships.

He said: "Charlie is very gullible when it comes to women. At times I think to myself, 'Here we go again'. He never seems to learn. I'm that close to him now I just say, 'Forget about it Charlie', but he never listens."

Paul is not afraid to criticise his criminal pal: "I have visited his mum a number of times and she is very disappointed in her son. Who can blame her? She has been destroyed by the situation. She knows if he hadn't done what he has been doing in prison he would have been out dozens of years ago."

But he will always stick up for Bronson if others criticise him: "He is hilariously funny and he can be caring as well. I have had a few problems and he has been the answer to them."

Would Paul be happy for Bronson to spend time with his kids? "Yes, I would. I don't think there would be any nervousness because he respects me too much.

"It was my son's birthday recently and Charlie sent me £70 to get him his favourite football strip. My kids have spoken to him and he tells them to behave themselves. He gives them good advice."

Paul's biography has now sold more than 13,000 copies. But Paul knows his friend is ultimately kept imprisoned by his own cult status.

He believes the more Charles Bronson sees his name in the papers, the more he will be encouraged to carry on with his violent antics.

He said: "They need each other, Charlie and the tabloid papers.

"He wants to be infamous, they want to sell papers and they make him infamous.

"While that carries on, he will never get out."