German paedophile Christian Brueckner, who is the prime suspect in the disappearance of Madeleine McCann, has written a letter addressing the claims for the first time. 

While in prison, Brueckner spoke about his drug dealing with a reporter for the German TV station SAT.1 as part of their detailed investigation into the case. 

The hour-long film is called "New clues in the case of missing Madeleine McCann". 

From his prison cell, he exchanged a series of letters with investigative reporter Jutta Rabe and admitted to being a drug dealer but claims he never abducted Madeleine. 

In one letter, to be shown in the TV documentary, Brueckner wrote: "I was never caught by the police because I followed a few key principles. 

"Where possible, only driving during the day so that my battered 'hippy bus' didn't attract attention, only driving on the roads I needed to and, most importantly, never provoking the police. 

"So that means not committing any crimes, certainly not abducting anyone." 

The suspect in the Madeleine McCann case claims it would have been "absurd" for him to have abducted the little girl because it would have risked his criminal life. 

It was previously found that Brueckner was familiar with the holiday complex McCann went missing from, after carrying out maintenance on the site. 

Mobile phone analysis by the TV station also claims to have established Brueckner was no more than five minutes away when Madeleine was taken from her bedroom on May 3, 2007. 

Prosecutors, who have worked on a case for three years, have said they have nearly enough evidence to charge Brueckner but he has yet to formally be arrested or questioned. 

Brueckner is currently serving a seven-year sentence in a German prison for the rape of an elderly American widow in Praia da Luz, Portugal, in 2005, two years before McCann vanished. 

German prosecutor Hans Wolters said last year they were 100 per cent sure that Brueckner was responsible but admitted all the evidence so far compiled was circumstantial. 

He said: "It is circumstantial evidence – we have no scientific evidence. 

"If we had a video of the act or a picture of Madeleine dead with Brueckner on camera, we wouldn't have had to make a public appeal. But we only have circumstantial evidence." 

But he also admitted prosecutors have no proof McCann is dead, any idea how she died and no evidence linking Brueckner to her alleged murder. 

"We have no body and no DNA but we have other evidence. Based on the evidence we have, it leads to no other conclusion. 

"I can't tell you on which basis we assume she is dead. But for us, there's no other possibility. There is no hope she is alive."