DNA from a mystery "sixth" person was found in the bedroom from which Madeleine McCann was abducted, it was claimed last night.

It does not match the DNA of either Gerry or Kate McCann or their three children, according to the Portuguese newspaper 24 Horas, which says the sample has been passed by police to the national forensic laboratories.

The paper also says the DNA does not match that of the case's only named suspect, the property developer Robert Murat.

The news emerged as Mr and Mrs McCann concluded a visit to the Spanish capital, Madrid, as part of their trail across Europe to publicise their daughter's disappearance.

They said they desperately hoped Madeleine's abductor was someone who wanted a daughter of their own and who would never harm her. They admitted they had thought the worst - that she might be in the hands of a paedophile or never found - but insisted they would not believe anything other than that she was safe and well.

Mr and Mrs McCann, both 38, were warmly received in Spain. In a news conference in front of nearly 20 television cameras, they made a special reference to a Spanish boy, Yeremi Vargas, who disappeared in March in Gran Canaria.

In return, a letter from the little boy's mother was presented to the McCanns, offering them support.

Mr McCann thought Madeleine's case should be examined in connection with other abductions. "I think it is at least worth exploring the possibility that her disappearance should not be considered in isolation, so putting it into context with other disappearances in the Iberian peninsula, even the Canary Isles as well," he said.

The McCanns plan to go to Berlin, Amsterdam and Morocco next week in their tireless search for Madeleine, who has now been missing for 30 days.
Meanwhile, the missing girl's aunt and uncle, Diane and John McCann, helped to release 400 yellow balloons to publicise the hunt for their niece. Pictures of Madeleine were attached to the balloons launched by youngsters from Bankhead Primary School in Glasgow, where Diane McCann is a teacher.

In Northern Ireland, pupils from four schools in Holywood, County Down, released 1,000 balloons in a show of solidarity.

It also emerged yesterday that 1,000 photographs have been uploaded by holidaymakers to a website set up in an attempt to identify Madeleine's kidnapper.

Computer experts are using the latest face-recognition technology to discover whether if any known paedophiles or criminals are in the background.

And more than 1,500 people have telephoned a police hotline in response to appeals for information.