The main suspect in Madeleine Macken's disappearance, Christian Brickner, has launched a letter-writing campaign to convince the public he had nothing to do with her disappearance 16 years ago from a holiday resort in Portugal.

Police suspicions about convicted sex offender Brickner sparked a major new development in the case this week as officers searched a dam about 50km from where Madeleine disappeared in Portugal.

The 45-year-old appears to have written a series of letters in the hope of drawing attention to his campaign to be cleared of any connection to the case, the Daily Mail points out.

Sinister letters written by Madeleine McCann prime suspect Christian Brueckner seen for the first time https://t.co/aETpBAM4Rn pic.twitter.com/EREqo1qMFn

- Daily Mail Online (@MailOnline) May 27, 2023

The letter, sent just days before the start of this week's inquests, makes clear his obsession with media to convince authorities and the public that he is innocent and had no involvement in Madeleine's abduction.

Graphologist Tracy Trussell, who examined the latest letter and others he sent over the past two years, said they showed Brickner was "deluded" and that his "fantasy views are fixed, unchanging."

She said his letters indicated someone who wanted to "rule and control" but also "someone who suffers from guilt". "Whatever the truth is, there is a need to constantly feed his ego and his ultimate goal is to get some kind of recognition," he continues.

Investigators investigating Brickner, who is serving seven years in prison for rape, insist they have "tangible evidence" that Madeleine is dead - and they believe he killed her.

In a May letter he writes: "You can never imagine what it's like when the whole world thinks you're a child killer and you're not."

He almost seems to revel in knowing he won't face a judge: “I was told a long time ago that Maddie's case was closed because there's not a shred of evidence. There will never be a trial.

"The prosecutors are not saying anything to the public because they have to give the files to my lawyers and they contain a lot of material that confirms my innocence.

The main theme in all his letters – all written in almost perfect English – is how he is "persecuted" by the prosecutors and complains of the psychological pressure being put on him, even talking about "torture".

"I am not in a position to say the actual treatment I am getting because I don't have the right words for it." Of course, all this is happening on the orders of the BKA (German criminal police)."

Brickner ends his letter by once again protesting that he has been scapegoated and remains firmly convinced that time will ultimately prove his innocence.