The suspected abductor and killer of Madeleine McCann still claims he had nothing to do with her disappearance, according to a new TV documentary.
Convicted rapist Christian Brueckner, 44, protested his innocence while exchanging letters with an investigative reporter.
He says his illegal activities as a drug dealer on the Algarve in Portugal meant he was careful not to commit any other crimes.
German prosecutors remain convinced he kidnapped Madeleine but Brueckner claims he is happy to "sit back and relax and just wait for their findings."
The letters, written in his prison cell, were sent to investigative reporter Jutta Rabe from German TV station SAT.1.
Brueckner admitted being a drug dealer and said he used his battered camper van to traffic drugs.
He 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."
Brueckner added that the idea he abducted Maddie was as "absurd...as starting a nuclear war or slaughtering a chicken."
Brueckner is currently being held in a high security prison in northern Germany.
He is serving a seven-year jail term for the rape of an American pensioner.
Brueckner was living in the Algarve when three-year-old Madeleine disappeared from her holiday villa in May 2007.
The new TV documentary, which is being broadcast this week, claims to have uncovered new evidence relating to the case.
This includes mobile phone analysis suggesting the sex offender was no more than five minutes away when the young girl was snatched.
They also spoke to a former online friend of Brueckner's who claimed he revealed paedophile fantasies.
He is said to have once written that he wanted to "capture something small and use it for days".
No charges have currently been brought against Brueckner in relation to Madeleine.
But makers of the documentary have sent evidence to public prosecutor Christian Wolters.
He said: "If this produces any ideas, we will of course follow them up."
It has also emerged separately that Brueckner was allegedly obsessed with women with bodies like pre-pubescent girls.
His former lover Nicole Fehlinger, 44, has been interviewed at least three times by detectives in Germany.
She met Brueckner in December 2006 at a friend's Christmas party.
Ms Fehlinger added: "He was nice and polite, but then our friendship became something more.
"He said he liked small bodies of women and he liked the bodies of girls before they reached puberty."
Ms Fehlinger, who split from Brueckner in late 2007, said his behaviour did not change after Maddie was reported missing.
She added: "Christian said she might have been taken by the underworld and the police will never find her."
*The new documentary, entitled 'New clues in the case of missing Madeleine McCann', will be screened in Germany tonight (Mon).