The key suspect in Madeleine McCann's case has been jailed for years. A new verdict could see him free.

A German court has acquitted a 47-year-old man on a series of charges, including three charges of aggravated rape and two charges of sexual abuse of children.

The man has been identified by local media as convicted paedophile, Christian Brueckner. He is simultaneously the prime suspect in the disappearance of Madeleine McCann, who went missing from her bedroom during a family holiday to Portugal back in 2007.

In this latest trial, he was charged, and then cleared, of the unrelated sexual offences.

While prosecutors called Brueckner a "dangerous psychopathic sadist" and called for 15 years jail time, the presiding judge said that he could "not be convicted of the acts he is accused of", and was thus acquitted.

Watch: Man suspected In Madeleine McCann case. Article continues after video.

Per the ABC, one of the allegations was that Brueckner entered a holiday apartment of a woman aged between 70 and 80 and tied her up before beating and sexually assaulting her.

Another charge saw him accused of entering an Irish woman's apartment via her balcony and raping her several times, while threatening her at knifepoint.

There were also allegations that he exposed himself in front of a 10-year-old German girl and 11-year-old Portugese girl. The charges were laid as a result of investigations into the disappearance of Madeleine McCann.

He was alleged to have committed these acts in Portugal between 2000 and 2017.

The defence raised doubts about these charges, which were largely based on testimony and not forensic evidence. They also pointed to what they labelled 'witnesses who were not credible', and suggested he might not have been charged if he had not also been a suspect in the McCann case.

He was cleared of However, Brueckner will remain in prison another year because he is still serving a seven-year sentence for rape in a different case, German news agency DPA reported. He was convicted in 2019 by the same Braunschweig German court for the rape of a 72-year-old American woman in Portugal in 2005.

The verdict can be appealed.

This latest trial has been followed widely, as his acquittal without further jailtime means that Brueckner could be released from jail as early as next year, per court officials to the ABC.

Madeleine McCann has been missing since 2007. Image: Getty.

Brueckner has not been charged in the McCann case, in which he is under investigation on suspicion of murder.

He spent many years in Portugal, including in the resort of Praia da Luz around the time of Madeleine's disappearance there in 2007. He has denied any involvement in her disappearance.

Despite allegations taking place in Portugal, Braunschweig state court has jurisdiction because Brueckner had his last German residence in that city in Lower Saxony.

Christian Brueckner. Image: Getty.

Feature image: Getty.

-With AAP