Madeleine McCann's mother was close to tears yesterday as she dismissed suggestions that her daughter was killed in her bedroom on the night that she disappeared from the family's apartment while they vacation in Portugal.

Kate McCann and her husband, Gerry, are expected to be interviewed again by detectives after reports that blood was found in their daughter's bedroom and evidence that it had contained a body.

The focus of the police investigation has shifted to the couple and the British friends who were with them in the Praia da Luz resort.

Click here for more from the Times of London

Police sources are reported to have abandoned the theory that Madeleine has been abducted and may still be alive. Officers are now convinced that Madeleine died in her bedroom as a result of "negligence or murder," claimed the Diário de Notícias newspaper. The McCanns, however, insisted that they still believed that Madeleine was alive when she was taken from the apartment 97 days ago.

"Last week when we met with the police they said, 'We are looking for a living child'. And they've said that a lot," Kate McCann said.

The couple refused to discuss reports that a speck of blood had been found by a British cadaver dog in the bedroom where the 4-year-old was sleeping, although Kate McCann was visibly upset when questioned. The blood sample will be sent for DNA analysis to see if it matches the girl or a kidnapper, but it may be too small to carry out the test.

"Kate and I strongly believe Madeleine was alive when she was taken from the apartment. Obviously what we don't know is what happened to her afterwards, who's taken her and what the motive is," Gerry McCann said.

"We're not naive, but on numerous occasions the Portuguese police have said they are looking for Madeleine alive and not Madeleine being murdered. I don't know of any information to have changed that," he added.

The couple are to be shown the photograph of a child snatcher who was in the area of Praia da Luz when their daughter disappeared. Urs Von Aesch, 67, killed himself last week while being hunted after abducting Ylenia Lenhard, a 5-year-old Swiss girl who looks like Madeleine.

Officers in St. Gallen, Switzerland, close to where Ylenia disappeared, have also reopened files on five other girls who disappeared in the area before von Aesch moved to Benimantell, which is near the Spanish coast.

A Swiss citizen, he was jailed in the 1960s after trying to blackmail a businessman by threatening to kidnap his young son. He went on to become a successful businessman before moving to Spain with his Spanish wife in about 1990.

The McCanns will be shown his photograph while they are questioned separately at the headquarters of the Polícia Judiciária in Portimão as part of a review of the entire investigation. They have already been interviewed twice at the headquarters.

A Renault car that had been used by the couple and their friends after Madeleine disappeared is still being investigated by police officers and forensic scientists. Tests have also been carried out on a car belonging to Robert Murat, the only official suspect in the case. The cars of his mother, his girlfriend, her estranged husband and Sergei Malinka, a web designer who had worked for Murat, have also been tested.

Gerry McCann said that he and his wife expected to be treated with the same thoroughness as anyone else in the investigation.

"We wouldn't expect it any other way," he said. "The same high levels will be applied to us as would be applied to anybody else, and that's only right and proper."

Madeleine was not seen alive by anyone apart from her parents for almost four hours on the night that she disappeared while sleeping in a room with the McCanns' 2-year-old twins, Amelie and Sean, it was claimed yesterday. She was put to bed at 6 p.m. and Gerry McCann said that he saw her an hour before his wife reported her missing at 10 p.m. Other friends in the group had checked on the apartment but had not entered the bedroom.

Portuguese police are reported to be concerned about inconsistencies between the statements given by the McCanns and their friends, three other couples and a single woman. The couples are Russell O'Brien and Jane Tanner, both 36, from Exeter, Fiona Payne, 34, and her husband, David, from Leicester, and Rachel Oldfield, 36, and her husband, Matthew, from London.

British and Portuguese police have been monitoring at least one of the friends and a worker connected to the Ocean Club resort, where the group stayed, although police have previously said that nobody in the group was a suspect.

A source close to the investigation said that the McCanns and their friends would be interviewed as part a routine review of the investigation being carried out with the help of British police officers. He said that possible traces of blood in Madeleine's ground-floor bedroom could have come from any of the hundreds of people who had stayed in the apartment in recent years.

Experts also cast doubt on claims that a British dog trained to track bodies had detected a scent in the bedroom. The body would have had to be in the room for at least several hours before leaving a detectable trace.

Murat has already been re-interviewed and a search of his home and garden over the weekend using British dogs and sonar equipment failed to reveal any trace of Madeleine.

Murat, who previously lived in Hockering, Norfolk, with his wife and young daughter, denies any involvement in the kidnapping.