A German court must "free itself" of the alleged connection between Christian Brückner and Madeleine McCann, his lawyer said, as his client faced an unrelated sex crime trial.
Friedrich Fülscher said outside court in Braunschweig there had been a media "pre-conviction" of Brückner due to him being repeatedly linked to Madeleine.
Brückner, 47, denies involvement in the McCann case and has never been charged.
He faces five unrelated charges in Lower Saxony, including three of rape.
Warning: You may find some of the details of the German case distressing
Mr Fülscher said outside court: "What we have is a media pre-conviction because he has been named as a suspect in this well-known missing person case.
"Otherwise, there would never have been such media interest. And that's what the court must free itself from."
The charges against Brückner were read out for the first time in detail during Friday morning's proceedings.
He faces three rape allegations and two of the sexual abuse of children in Portugal between 2000 and 2017.
The charges he faces in full:
At some point between 2000 and 2006: The rape of an unidentified woman aged between 70 and 80 in a holiday home in Portugal
At some point between 2000 and 2006: The rape of a German-speaking girl believed to have been at least 14 years old in his home in Praia da Luz
2004: The rape of a 20-year-old Irish woman after entering her apartment in Praia da Rocha
2007: The sexual abuse of a 10-year-old German girl on a beach in Salema, Faro
2017: The sexual abuse of an 11-year-old Portuguese girl in a playground in Bartolomeu de Messines
His defence team suggested it would challenge two of the rape charges based on the statute of limitations and because of insufficient evidence on when those alleged offences might have been committed.
They will deny Brückner's involvement in the rape in Praia de Rocha in 2004.
They told the court they regarded key witnesses as "unreliable" due to known drug or alcohol issues.
The lawyers said they would challenge one of the child sex abuse charges on the basis that children can be susceptible to "suggestive questioning".
The defence also applied to have items of evidence thrown out. It claimed that USB sticks found on land in Saxony-Anhalt in 2016 were illegally obtained.
McCann suspect in German trial for unrelated rape
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The defence also said that the prosecution had failed to disclose important information about investigations into its client.
It claimed federal police had been involved in bugging Brückner's prison cell to try to catch him incriminating himself in the Madeline McCann investigation - meaning conversations with his lawyer may have been illicitly recorded.
They also said an undercover investigator had been sent into prison where Brückner was being held to try to provoke the suspect into talking about Madeline - something the defence claims was unsuccessful but should have been disclosed.
"At the core is the problem that the investigation into Maddie McCann cannot be separated from the investigation into these cases which are the subject of this trial," Mr Fülscher said outside court.
"The federal police have just one file but the prosecution selected only certain aspects for this trial. In our view that is not legally correct and we have right to access all files in this investigation."
Last week, proceedings were abruptly suspended after Brückner's lawyers objected to the suitability of a lay judge.
Brückner sat largely motionless through the proceedings.
The trial is expected to resume next Friday.
Three-year-old Madeleine McCann vanished from a holiday apartment in Praia da Luz in Portugal's Algarve region, in 2007. It remains one of the highest-profile missing persons cases in the world.
Brückner identified as a suspect by German investigators in June 2020, in what they have classed as a murder inquiry. He was subsequently made an arguido, or formal suspect, by Portuguese authorities.
However no formal charges have ever been brought, and the full details of the German investigation have never been released.
