A spokesman for the Aachen police, Robert Hintereker, told Bild am Sonntag that the public prosecutor would decide in the coming days whether to take a DNA sample from the British-born suspect who is being treated for throat cancer in a hospital in the city.

But Aachen’s main public prosecutor Robert Deller told news agency ddp Hewlett’s possible link to Madeleine’s disappearance was “pure speculation.” He said that British authorities were seeking legal aid to question the suspect for a rape case dating back to 1975.

The 64-year-old, identified as Raymond Hewlett, is reported to have been convicted and jailed in three cases of sexually assaulting young girls. He is reported to be together with a German and have worked in the past years on fishing boats and as a performer at fair grounds.

Hewlett is alleged to have been staying near the McCann’s holiday apartment in Praia da Luz in Portugal when their daughter Madeleine went missing in May 2007.

Media reports say a British couple who vacationed in Portugal and met Hewlett at a camping place went to the police after reading about Hewlett’s criminal background in a newspaper.

Hewlett, a former soldier, is said to bear a striking resemblance to one of the police sketches of possible suspects that were made after Madeleine’s disappearance. Police in Portugal reportedly quizzed Hewlett at the time but found he had an alibi.

Media reports say British authorities as well as private detectives hired by the McCanns are interested in questioning Hewlett.

British newspaper The Sun quoted a nurse in the Aachen hospital saying that Hewlett, who is being treated for cancer in the intensive care unit, was too ill to be interviewed.

Madeleine was nearly four when she went missing from her family’s holiday apartment on May 3, 2007, while her parents dined with friends nearby. She has not been found despite a massive police investigation and huge publicity worldwide.