"We're not naive, but on numerous occasions the Portuguese police have said they are looking for Madeleine alive . I don't know of any information to have changed that.
“They are working incredibly hard and very long hours. They are absolutely determined to find Madeleine."
His wife said: “We are very happy with the way the investigation is going and we have said that from an early stage.”
Police are expected to ask the McCanns, from Rothley, Leicestershire, to confirm their movements and those of the seven other British adults who were on holiday with them in the Algarve when Madeleine disappeared 96 days ago.
They will be questioned separately at the headquarters of the Polícia Judiciária in Portimao as part of a review led by by British detectives of the entire investigation. They have already been interviewed twice at the headquarters.
A Jeep used by the couple on their holiday in Praia da Luz was still being tested by forensic science experts and sniffer dogs today. Tests have also been carried out on a car belonging to Robert Murat, the only official suspect in the case, his mother, his girlfriend, her estranged husband and Serguei Malinka, a Russian web designer who had worked for Mr Murat.
Portuguese newspapers have reported that detectives are now investigating whether Madeleine was killed in the bedroom, either deliberately or by accident, by someone she knew.
Police have previously stressed that the McCanns and their friends have not been considered suspects.
Correio da Manhã, a Portuguese newspaper, reported today that Madeleine's parents were the last people to see her alive, between 6pm and 9pm on May 3.
Mr McCann, 39, has told police that he last saw Madeleine in her bed shortly after 9pm. His wife, 38, said she discovered their daughter missing when she checked at 10pm.
Other friends within the party said they checked on the apartment between those times but are not believed to have entered the front bedroom where Madeleine was sleeping with 2-year-old twins Amelie and Sean.
The McCann family was on a week’s holiday with three other couples and their children and a single woman. The couples are Dr Russell O’Brien and Jane Tanner, both 36, from Exeter, Dr Fiona Payne, 34, and her husband David from Leicester, and Rachel Oldfield, 36, and her husband Matthew, from London.
Miss Tanner told police that she saw man carrying a child close to the McCann’s apartment at about 9.15pm on the night Madeleine disappeared, leading to the theroy that she had been abducted by a stranger.
British and Portuguese police have been monitoring the movements of a British tourist who has at the Ocean Club resort when Madeleine disappeared. A Portuguese worker connected to the resort has also been under surveillance.
